btrfs: don't leak ret from do_chunk_alloc

If we're trying to make a data reservation and we have to allocate a
data chunk we could leak ret == 1, as do_chunk_alloc() will return 1 if
it allocated a chunk.  Since the end of the function is the success path
just return 0.

CC: [email protected] # 4.4+
Signed-off-by: Josef Bacik <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Signed-off-by: David Sterba <[email protected]>

Author: josefbacik

fs/btrfs/extent-tree.c

@@ -4226,7 +4226,7 @@ int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes)
 				      data_sinfo->flags, bytes, 1);
 	spin_unlock(&data_sinfo->lock);
 
-	return ret;
+	return 0;
 }
 
 int btrfs_check_data_free_space(struct inode *inode,