Fixup SDK's vet usage to use go vet with build tags (#2300)

Updates the SDK's usage of vet to use go vet instead of go tool vet.
This allows the SDK to pass build tags and packages instead of just
folder paths to the tool.

Fixes SDK's CI test failure with Go Tip.

Makefile

@@ -166,11 +166,11 @@ lint:
 	echo "$$lint"; \
 	if [ "$$lint" != "" ]; then exit 1; fi
 
-SDK_BASE_FOLDERS=$(shell ls -d */ | grep -v vendor | grep -v awsmigrate)
-GO_VET_CMD=go tool vet --all -shadow
+SDK_BASE_FOLDERS=$(shell go list ./... | grep -v vendor | grep -v awsmigrate)
 
 vet:
-	${GO_VET_CMD} ${SDK_BASE_FOLDERS}
+	@echo "go vet SDK packages"
+	@go vet -tags "example codegen integration" -all ${SDK_BASE_FOLDERS}
 
 get-deps: get-deps-tests get-deps-x-tests get-deps-codegen get-deps-verify
 

private/model/api/examples_builder.go

@@ -162,7 +162,6 @@ func (builder defaultExamplesBuilder) BuildScalar(name, memName string, ref *Sha
 	default:
 		panic(fmt.Errorf("Unsupported scalar type: %v", reflect.TypeOf(v)))
 	}
-	return ""
 }
 
 func (builder defaultExamplesBuilder) BuildComplex(name, memName string, ref *ShapeRef, v map[string]interface{}) string {
@@ -180,8 +179,6 @@ func (builder defaultExamplesBuilder) BuildComplex(name, memName string, ref *Sh
 	default:
 		panic(fmt.Sprintf("Expected complex type but recieved %q", ref.Shape.Type))
 	}
-
-	return ""
 }
 
 func (builder defaultExamplesBuilder) GoType(ref *ShapeRef, elem bool) string {

private/model/api/passes.go

@@ -81,7 +81,6 @@ func (r *referenceResolver) resolveReference(ref *ShapeRef) {
 	shape, ok := r.API.Shapes[ref.ShapeName]
 	if !ok {
 		panic(fmt.Sprintf("unable resolve reference, %s", ref.ShapeName))
-		return
 	}
 
 	if ref.JSONValue {