cmd: drop args to MountImage to use with vfs

the vfs driver does not create any mount, so it doesn't accept any
argument passed to MountImage.  Drop the arguments so mount image can
be used in the tests suite.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

cmd/containers-storage/mount.go

@@ -22,7 +22,7 @@ func mount(flags *mflag.FlagSet, action string, m storage.Store, args []string)
 	moes := []mountPointOrError{}
 	for _, arg := range args {
 		if paramReadOnly {
-			result, err := m.MountImage(arg, []string{"noexec", "nosuid"}, paramMountLabel)
+			result, err := m.MountImage(arg, []string{}, paramMountLabel)
 			errText := ""
 			if err != nil {
 				errText = err.Error()