btrfs: Remove WARN_ON in walk_log_tree

The log_root passed to walk_log_tree is guaranteed to have its
root_key.objectid always be BTRFS_TREE_LOG_OBJECTID. This is by
merit that all log roots of an ordinary root are allocated in
alloc_log_tree which hard-codes objectid to be BTRFS_TREE_LOG_OBJECTID.

In case walk_log_tree is called for a log tree found by btrfs_read_fs_root
in btrfs_recover_log_trees, that function already ensures
found_key.objectid is BTRFS_TREE_LOG_OBJECTID.

No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

@@ -2894,8 +2894,6 @@ static int walk_log_tree(struct btrfs_trans_handle *trans,
 					clear_extent_buffer_dirty(next);
 			}
 
-			WARN_ON(log->root_key.objectid !=
-				BTRFS_TREE_LOG_OBJECTID);
 			ret = btrfs_pin_reserved_extent(fs_info, next->start,
 							next->len);
 			if (ret)