btrfs: remove pointless return value assignment at btrfs_finish_one_ordered()

At btrfs_finish_one_ordered() it's pointless to assign 0 to the 'ret'
variable because if it has a non-zero value (error), we have already
jumped to the 'out' label. So remove that redundant assignment.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -3184,7 +3184,6 @@ int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent)
 		btrfs_abort_transaction(trans, ret);
 		goto out;
 	}
-	ret = 0;
 out:
 	clear_extent_bit(&inode->io_tree, start, end, clear_bits,
 			 &cached_state);