btrfs: make close_ctree return void

There's no user of the return value and we can get rid of the comment in
put_super.
Signed-off-by: NDavid Sterba <dsterba@suse.cz>
Signed-off-by: NChris Mason <clm@fb.com>

fs/btrfs/disk-io.c

@@ -3623,7 +3623,7 @@ int btrfs_commit_super(struct btrfs_root *root)
 	return btrfs_commit_transaction(trans, root);
 }
 
-int close_ctree(struct btrfs_root *root)
+void close_ctree(struct btrfs_root *root)
 {
 	struct btrfs_fs_info *fs_info = root->fs_info;
 	int ret;
@@ -3711,8 +3711,6 @@ int close_ctree(struct btrfs_root *root)
 
 	btrfs_free_block_rsv(root, root->orphan_block_rsv);
 	root->orphan_block_rsv = NULL;
-
-	return 0;
 }
 
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,

fs/btrfs/disk-io.h

@@ -56,7 +56,7 @@ void clean_tree_block(struct btrfs_trans_handle *trans,
 int open_ctree(struct super_block *sb,
 	       struct btrfs_fs_devices *fs_devices,
 	       char *options);
-int close_ctree(struct btrfs_root *root);
+void close_ctree(struct btrfs_root *root);
 int write_ctree_super(struct btrfs_trans_handle *trans,
 		      struct btrfs_root *root, int max_mirrors);
 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);

fs/btrfs/super.c

@@ -307,13 +307,7 @@ void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
 
 static void btrfs_put_super(struct super_block *sb)
 {
-	(void)close_ctree(btrfs_sb(sb)->tree_root);
-	/* FIXME: need to fix VFS to return error? */
-	/* AV: return it _where_?  ->put_super() can be triggered by any number
-	 * of async events, up to and including delivery of SIGKILL to the
-	 * last process that kept it busy.  Or segfault in the aforementioned
-	 * process...  Whom would you report that to?
-	 */
+	close_ctree(btrfs_sb(sb)->tree_root);
 }
 
 enum {