btrfs: remove lock protection for BLOCK_GROUP_FLAG_RELOCATING_REPAIR

Before when this was modifying the bit field we had to protect it with
the bg->lock, however now we're using bit helpers so we can stop
using the bg->lock.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -8279,13 +8279,10 @@ bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical)
 	if (!cache)
 		return true;
 
-	spin_lock(&cache->lock);
 	if (test_and_set_bit(BLOCK_GROUP_FLAG_RELOCATING_REPAIR, &cache->runtime_flags)) {
-		spin_unlock(&cache->lock);
 		btrfs_put_block_group(cache);
 		return true;
 	}
-	spin_unlock(&cache->lock);
 
 	kthread_run(relocating_repair_kthread, cache,
 		    "btrfs-relocating-repair");