mtip32xx: use DEFINE_SPINLOCK() for spinlock

spinlock can be initialized automatically with DEFINE_SPINLOCK()
rather than explicitly calling spin_lock_init().
Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Link: https://lore.kernel.org/r/20210329095349.4170870-1-liushixin2@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/mtip32xx/mtip32xx.c

@@ -97,7 +97,7 @@ static int instance;
 
 static struct list_head online_list;
 static struct list_head removing_list;
-static spinlock_t dev_lock;
+static DEFINE_SPINLOCK(dev_lock);
 
 /*
  * Global variable used to hold the major block device number
@@ -4363,8 +4363,6 @@ static int __init mtip_init(void)
 
 	pr_info(MTIP_DRV_NAME " Version " MTIP_DRV_VERSION "\n");
 
-	spin_lock_init(&dev_lock);
-
 	INIT_LIST_HEAD(&online_list);
 	INIT_LIST_HEAD(&removing_list);