btrfs: remove redundant check on ret being non-zero

The error return variable ret is initialized to zero and then is
checked to see if it is non-zero in the if-block that follows it.
It is therefore impossible for ret to be non-zero after the if-block
hence the check is redundant and can be removed.

Detected by CoverityScan, CID#1021040 ("Logically dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

@@ -1143,8 +1143,6 @@ again:
 				goto again;
 			}
 			kfree(victim_name);
-			if (ret)
-				return ret;
 next:
 			cur_offset += victim_name_len + sizeof(*extref);
 		}