debugfs: convert gid= argument from decimal, not octal

This patch technically breaks userspace, but I suspect that anyone who
actually used this flag would have encountered this brokenness, declared
it lunacy, and already sent a patch.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/debugfs/inode.c

@@ -176,7 +176,7 @@ static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts)
 			opts->uid = uid;
 			break;
 		case Opt_gid:
-			if (match_octal(&args[0], &option))
+			if (match_int(&args[0], &option))
 				return -EINVAL;
 			gid = make_kgid(current_user_ns(), option);
 			if (!gid_valid(gid))