verify that DisableFlagsInUseLine is set for all commands

This replaces the visitAll recursive function with a test that verifies that
the option is set for all commands and subcommands, so that it doesn't have
to be modified at runtime.

We currently still have to loop over all functions for the setValidateArgs
call, but that can be looked at separately.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/image/pull.go

@@ -38,7 +38,8 @@ func newPullCommand(dockerCLI command.Cli) *cobra.Command {
 			"category-top": "5",
 			"aliases":      "docker image pull, docker pull",
 		},
-		ValidArgsFunction: cobra.NoFileCompletions,
+		ValidArgsFunction:     cobra.NoFileCompletions,
+		DisableFlagsInUseLine: true,
 	}
 
 	flags := cmd.Flags()