virtio_blk: Use kmalloc_array() in init_vq()

Multiplications for the size determination of memory allocations
indicated that array data structures should be processed.
Thus use the corresponding function "kmalloc_array".

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/block/virtio_blk.c

@@ -390,13 +390,13 @@ static int init_vq(struct virtio_blk *vblk)
 	if (err)
 		num_vqs = 1;
 
-	vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL);
+	vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL);
 	if (!vblk->vqs)
 		return -ENOMEM;
 
-	names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL);
-	callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL);
-	vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL);
+	names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL);
+	callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL);
+	vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL);
 	if (!names || !callbacks || !vqs) {
 		err = -ENOMEM;
 		goto out;