btrfs: Consolidate error checking for btrfs_alloc_chunk

The second if is really a subcase of ret being less than 0. So
introduce a generic if (ret < 0) check, and inside have another if
which explicitly handles the -ENOSPC and any other errors. 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/extent-tree.c

@@ -4681,12 +4681,14 @@ again:
 	trans->allocating_chunk = false;
 
 	spin_lock(&space_info->lock);
-	if (ret < 0 && ret != -ENOSPC)
-		goto out;
-	if (ret)
-		space_info->full = 1;
-	else
+	if (ret < 0) {
+		if (ret == -ENOSPC)
+			space_info->full = 1;
+		else
+			goto out;
+	} else {
 		ret = 1;
+	}
 
 	space_info->force_alloc = CHUNK_ALLOC_NO_FORCE;
 out: