Switch functional options with no args to vars

This switches functional arguments with no variables to not taking
arguments, meaning that they can be called like

```go
r.Update(ctx, obj, client.UpdateDryRunAll)
```

instead of

```go
r.Update(ctx, obj, client.UpdateDryRunAll())
```

Options with arguments still get called as functions.

pkg/client/client_test.go

@@ -276,7 +276,7 @@ var _ = Describe("Client", func() {
 					Expect(cl).NotTo(BeNil())
 
 					By("creating the object (with DryRun)")
-					err = cl.Create(context.TODO(), dep, client.CreateDryRunAll())
+					err = cl.Create(context.TODO(), dep, client.CreateDryRunAll)
 					Expect(err).NotTo(HaveOccurred())
 
 					actual, err := clientset.AppsV1().Deployments(ns).Get(dep.Name, metav1.GetOptions{})
@@ -415,7 +415,7 @@ var _ = Describe("Client", func() {
 				})
 
 				By("creating the object")
-				err = cl.Create(context.TODO(), u, client.CreateDryRunAll())
+				err = cl.Create(context.TODO(), u, client.CreateDryRunAll)
 				Expect(err).NotTo(HaveOccurred())
 
 				actual, err := clientset.AppsV1().Deployments(ns).Get(dep.Name, metav1.GetOptions{})
@@ -1074,7 +1074,7 @@ var _ = Describe("Client", func() {
 				Expect(err).NotTo(HaveOccurred())
 
 				By("patching the Deployment with dry-run")
-				err = cl.Patch(context.TODO(), dep, client.ConstantPatch(types.MergePatchType, mergePatch), client.PatchDryRunAll())
+				err = cl.Patch(context.TODO(), dep, client.ConstantPatch(types.MergePatchType, mergePatch), client.PatchDryRunAll)
 				Expect(err).NotTo(HaveOccurred())
 
 				By("validating patched Deployment doesn't have the new annotation")
@@ -1183,7 +1183,7 @@ var _ = Describe("Client", func() {
 					Kind:    "Deployment",
 					Version: "v1",
 				})
-				err = cl.Patch(context.TODO(), u, client.ConstantPatch(types.MergePatchType, mergePatch), client.PatchDryRunAll())
+				err = cl.Patch(context.TODO(), u, client.ConstantPatch(types.MergePatchType, mergePatch), client.PatchDryRunAll)
 				Expect(err).NotTo(HaveOccurred())
 
 				By("validating patched Deployment does not have the new annotation")
@@ -2000,7 +2000,7 @@ var _ = Describe("Client", func() {
 	Describe("CreateOptions", func() {
 		It("should allow setting DryRun to 'all'", func() {
 			co := &client.CreateOptions{}
-			client.CreateDryRunAll()(co)
+			client.CreateDryRunAll(co)
 			all := []string{metav1.DryRunAll}
 			Expect(co.AsCreateOptions().DryRun).To(Equal(all))
 		})
@@ -2141,7 +2141,7 @@ var _ = Describe("Client", func() {
 	Describe("UpdateOptions", func() {
 		It("should allow setting DryRun to 'all'", func() {
 			uo := &client.UpdateOptions{}
-			client.UpdateDryRunAll()(uo)
+			client.UpdateDryRunAll(uo)
 			all := []string{metav1.DryRunAll}
 			Expect(uo.AsUpdateOptions().DryRun).To(Equal(all))
 		})
@@ -2157,7 +2157,7 @@ var _ = Describe("Client", func() {
 	Describe("PatchOptions", func() {
 		It("should allow setting DryRun to 'all'", func() {
 			po := &client.PatchOptions{}
-			client.PatchDryRunAll()(po)
+			client.PatchDryRunAll(po)
 			all := []string{metav1.DryRunAll}
 			Expect(po.AsPatchOptions().DryRun).To(Equal(all))
 		})

pkg/client/options.go

@@ -67,10 +67,8 @@ type CreateOptionFunc func(*CreateOptions)
 
 // CreateDryRunAll is a functional option that sets the DryRun
 // field of a CreateOptions struct to metav1.DryRunAll.
-func CreateDryRunAll() CreateOptionFunc {
-	return func(opts *CreateOptions) {
-		opts.DryRun = []string{metav1.DryRunAll}
-	}
+var CreateDryRunAll CreateOptionFunc = func(opts *CreateOptions) {
+	opts.DryRun = []string{metav1.DryRunAll}
 }
 
 // DeleteOptions contains options for delete requests. It's generally a subset
@@ -339,10 +337,8 @@ type UpdateOptionFunc func(*UpdateOptions)
 
 // UpdateDryRunAll is a functional option that sets the DryRun
 // field of a UpdateOptions struct to metav1.DryRunAll.
-func UpdateDryRunAll() UpdateOptionFunc {
-	return func(opts *UpdateOptions) {
-		opts.DryRun = []string{metav1.DryRunAll}
-	}
+var UpdateDryRunAll UpdateOptionFunc = func(opts *UpdateOptions) {
+	opts.DryRun = []string{metav1.DryRunAll}
 }
 
 // PatchOptions contains options for patch requests.
@@ -398,22 +394,21 @@ func (o *PatchOptions) AsPatchOptions() *metav1.PatchOptions {
 // https://github.com/tmrts/go-patterns/blob/master/idiom/functional-options.md.
 type PatchOptionFunc func(*PatchOptions)
 
+// ForceOwnership sets the Force option, indicating that
+// in case of conflicts with server-side apply, the client should
+// acquire ownership of the conflicting field.  Most controllers
+// should use this.
+var ForceOwnership PatchOptionFunc = func(opts *PatchOptions) {
+	definitelyTrue := true
+	opts.Force = &definitelyTrue
+}
+
 // PatchDryRunAll is a functional option that sets the DryRun
 // field of a PatchOptions struct to metav1.DryRunAll.
-func PatchDryRunAll() PatchOptionFunc {
-	return func(opts *PatchOptions) {
-		opts.DryRun = []string{metav1.DryRunAll}
-	}
+var PatchDryRunAll PatchOptionFunc = func(opts *PatchOptions) {
+	opts.DryRun = []string{metav1.DryRunAll}
 }
 
-// ForceOwnership is a functional option that sets the Force
-// field of a PatchOptions struct to true.
-func ForceOwnership() PatchOptionFunc {
-	force := true
-	return func(opts *PatchOptions) {
-		opts.Force = &force
-	}
-}
 
 // FieldOwner set the field manager name for the given server-side apply patch.
 func FieldOwner(name string) PatchOptionFunc {