Revert "rdctl: Don't use process groups on Linux"

This reverts commit ea31ee9.  Now that we
manually sets process groups on Linux (in the previous commit), we can
turn its use back on.

Signed-off-by: Mark Yen <mark.yen@suse.com>

src/go/rdctl/cmd/internalProcessWaitKill.go

@@ -21,7 +21,6 @@ package cmd
 
 import (
 	"fmt"
-	"runtime"
 
 	"github.com/rancher-sandbox/rancher-desktop/src/go/rdctl/pkg/process"
 	"github.com/spf13/cobra"
@@ -40,12 +39,6 @@ exit, and once it does, terminates all processes within the same process group.`
 		if err != nil {
 			return fmt.Errorf("failed to get process ID: %w", err)
 		}
-		if runtime.GOOS == "linux" {
-			// TODO: We can't use the process group on Linux, because Electron does
-			// not always create a new one.  But for now still wait for the
-			// process to exit
-			return process.WaitForProcess(pid)
-		}
 		return process.KillProcessGroup(pid, true)
 	},
 }

src/go/rdctl/pkg/shutdown/shutdown.go

@@ -237,21 +237,17 @@ func terminateRancherDesktopFunc(appDir string) func(context.Context) error {
 	return func(ctx context.Context) error {
 		var errors *multierror.Error
 
-		// TODO: We can't use the process group on Linux, because Electron does
-		// not always create a new one.
-		if runtime.GOOS != "linux" {
-			errors = multierror.Append(errors, (func() error {
-				mainExe, err := p.GetMainExecutable(ctx)
-				if err != nil {
-					return err
-				}
-				pid, err := process.FindPidOfProcess(mainExe)
-				if err != nil {
-					return err
-				}
-				return process.KillProcessGroup(pid, false)
-			})())
-		}
+		errors = multierror.Append(errors, (func() error {
+			mainExe, err := p.GetMainExecutable(ctx)
+			if err != nil {
+				return err
+			}
+			pid, err := process.FindPidOfProcess(mainExe)
+			if err != nil {
+				return err
+			}
+			return process.KillProcessGroup(pid, false)
+		})())
 
 		errors = multierror.Append(errors, process.TerminateProcessInDirectory(appDir, true))