btrfs: adjust message level for unrecognized mount option

An unrecognized option is a failure that should get user/administrator
attention, the info level is often below what gets logged, so make it
error.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/super.c

@@ -873,7 +873,7 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 			break;
 #endif
 		case Opt_err:
-			btrfs_info(info, "unrecognized mount option '%s'", p);
+			btrfs_err(info, "unrecognized mount option '%s'", p);
 			ret = -EINVAL;
 			goto out;
 		default: