btrfs: simplify return values in btrfs_check_raid_min_devices

Function btrfs_check_raid_min_devices() returns error code from the enum
btrfs_err_code and it starts from 1. So there is no need to check if ret
is > 0. So drop this check and also drop the local variable ret.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/volumes.c

@@ -1949,12 +1949,8 @@ static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info,
 		if (!(all_avail & btrfs_raid_array[i].bg_flag))
 			continue;
 
-		if (num_devices < btrfs_raid_array[i].devs_min) {
-			int ret = btrfs_raid_array[i].mindev_error;
-
-			if (ret)
-				return ret;
-		}
+		if (num_devices < btrfs_raid_array[i].devs_min)
+			return btrfs_raid_array[i].mindev_error;
 	}
 
 	return 0;