btrfs: convert log messages to error level in btrfs_replay_log()

We are logging messages as warnings but they should really have an error
level instead, as if the respective conditions are met the mount will
fail. So convert them to error level and also log the error code returned
by read_tree_block().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Author: fdmanana

fs/btrfs/disk-io.c

@@ -1994,7 +1994,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 	int level = btrfs_super_log_root_level(disk_super);
 
 	if (unlikely(fs_devices->rw_devices == 0)) {
-		btrfs_warn(fs_info, "log replay required on RO media");
+		btrfs_err(fs_info, "log replay required on RO media");
 		return -EIO;
 	}
 
@@ -2008,9 +2008,9 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 	check.owner_root = BTRFS_TREE_LOG_OBJECTID;
 	log_tree_root->node = read_tree_block(fs_info, bytenr, &check);
 	if (IS_ERR(log_tree_root->node)) {
-		btrfs_warn(fs_info, "failed to read log tree");
 		ret = PTR_ERR(log_tree_root->node);
 		log_tree_root->node = NULL;
+		btrfs_err(fs_info, "failed to read log tree with error: %d", ret);
 		btrfs_put_root(log_tree_root);
 		return ret;
 	}