btrfs: cleanup temporary variables when finding rotational device status

The pointer to struct request_queue is used only to get device type
rotating or the non-rotating. So use it directly.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
1 file changed