dma: idxd: use DEFINE_MUTEX() for mutex lock

mutex lock can be initialized automatically with DEFINE_MUTEX()
rather than explicitly calling mutex_init().
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20201224132254.30961-1-zhengyongjun3@huawei.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/idxd/init.c

@@ -31,7 +31,7 @@ MODULE_AUTHOR("Intel Corporation");
 bool support_enqcmd;
 
 static struct idr idxd_idrs[IDXD_TYPE_MAX];
-static struct mutex idxd_idr_lock;
+static DEFINE_MUTEX(idxd_idr_lock);
 
 static struct pci_device_id idxd_pci_tbl[] = {
 	/* DSA ver 1.0 platforms */
@@ -544,7 +544,6 @@ static int __init idxd_init_module(void)
 	else
 		support_enqcmd = true;
 
-	mutex_init(&idxd_idr_lock);
 	for (i = 0; i < IDXD_TYPE_MAX; i++)
 		idr_init(&idxd_idrs[i]);