btrfs: remove a useless return statement in btrfs_block_rsv_add

Since ret must be 0 here, don't have to return.  No functional change
and code readability is not hurt.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
1 file changed