replace hardcoded use of "kubectl" in apply warning msg

pkg/kubectl/cmd/cmd.go

@@ -337,7 +337,7 @@ func NewKubectlCommand(f cmdutil.Factory, in io.Reader, out, err io.Writer) *cob
 		{
 			Message: "Advanced Commands:",
 			Commands: []*cobra.Command{
-				NewCmdApply(f, out, err),
+				NewCmdApply("kubectl", f, out, err),
 				NewCmdPatch(f, out),
 				NewCmdReplace(f, out),
 				deprecatedAlias("update", NewCmdReplace(f, out)),