btrfs: clear log tree recovering status if starting transaction fails

When a log recovery is in progress, lots of operations have to take that
into account, so we keep this status per tree during the operation. Long
time ago error handling revamp patch 79787eaa ("btrfs: replace many
BUG_ONs with proper error handling") removed clearing of the status in
an error branch. Add it back as was intended in e02119d5 ("Btrfs:
Add a write ahead tree log to optimize synchronous operations").

There are probably no visible effects, log replay is done only during
mount and if it fails all structures are cleared so the stale status
won't be kept.

Fixes: 79787eaa ("btrfs: replace many BUG_ONs with proper error handling")
Reviewed-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

@@ -6372,6 +6372,7 @@ int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
 error:
 	if (wc.trans)
 		btrfs_end_transaction(wc.trans);
+	clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
 	btrfs_free_path(path);
 	return ret;
 }