Btrfs: Check CAP_DAC_READ_SEARCH for BTRFS_IOC_INO_PATHS

CAP_DAC_READ_SEARCH overrides read and search permission check on
file and directory. It seems fit for BTRFS_IOC_INO_PATHS.
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

fs/btrfs/ioctl.c

@@ -3290,7 +3290,7 @@ static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
 	struct inode_fs_paths *ipath = NULL;
 	struct btrfs_path *path;
 
-	if (!capable(CAP_SYS_ADMIN))
+	if (!capable(CAP_DAC_READ_SEARCH))
 		return -EPERM;
 
 	path = btrfs_alloc_path();