Cleanup: use the cobra fix for persistent hooks traversal

We upgraded cobra to 1.8.0 with #329.
So we can use its fix for persistent hooks traversal spf13/cobra#2044,
instead of our workaround for it from #312.

Signed-off-by: Volodymyr Khoroz <volodymyr.khoroz@foundries.io>

cmd/root.go

@@ -70,7 +70,7 @@ func Execute() {
 }
 
 func init() {
-	cobra.OnInitialize(func() { fixPersistentPreRuns(rootCmd) })
+	cobra.EnableTraverseRunHooks = true
 	cobra.OnInitialize(initConfig)
 
 	rootCmd.PersistentFlags().StringVarP(&cfgFile, "config", "c", "", "config file (default is $HOME/.config/fioctl.yaml)")
@@ -213,59 +213,3 @@ $ fioctl completion fish > ~/.config/fish/completions/fioctl.fish
 		}
 	},
 }
-
-func fixPersistentPreRuns(cmd *cobra.Command) {
-	// See https://github.com/spf13/cobra/issues/216
-	parentPreRunE := cmd.PersistentPreRunE
-	parentPreRun := cmd.PersistentPreRun
-	// First, traverse up to find a parent defining the PersistentPreRun function.
-	for p := cmd.Parent(); p != nil && parentPreRunE == nil && parentPreRun == nil; p = p.Parent() {
-		// Cobra prefers PersistentPreRunE over PersistentPreRun if both are defined, so do we.
-		// Actually, no our code defines both functions (expected), so that assumption is safe.
-		if p.PersistentPreRunE != nil {
-			parentPreRunE = p.PersistentPreRunE
-		} else if p.PersistentPreRun != nil {
-			parentPreRun = p.PersistentPreRun
-		}
-	}
-
-	// Traverse children tree top-down, gradually fixing their PersistentPreRun functions to call into parents.
-	for _, child := range cmd.Commands() {
-		preRun := child.PersistentPreRun
-		preRunE := child.PersistentPreRunE
-		if preRunE != nil {
-			if parentPreRunE != nil {
-				child.PersistentPreRunE = func(cmd *cobra.Command, args []string) error {
-					if err := parentPreRunE(cmd, args); err != nil {
-						return err
-					}
-					return preRunE(cmd, args)
-				}
-			} else if parentPreRun != nil {
-				child.PersistentPreRunE = func(cmd *cobra.Command, args []string) error {
-					parentPreRun(cmd, args)
-					return preRunE(cmd, args)
-				}
-			}
-		} else if preRun != nil {
-			if parentPreRunE != nil {
-				// Set the PersistentPreRunE, not PersistentPreRun, so that we can return the parent error into cmd.execute.
-				child.PersistentPreRun = nil
-				child.PersistentPreRunE = func(cmd *cobra.Command, args []string) error {
-					if err := parentPreRunE(cmd, args); err != nil {
-						return err
-					}
-					preRun(cmd, args)
-					return nil
-				}
-			} else if parentPreRun != nil {
-				child.PersistentPreRun = func(cmd *cobra.Command, args []string) {
-					parentPreRun(cmd, args)
-					preRun(cmd, args)
-				}
-			}
-		}
-		// Now that this child command was fixed, we can run the magic recursion.
-		fixPersistentPreRuns(child)
-	}
-}