bdev/virtio: check allocation in virtio_user_dev_init()

Change-Id: Ib8cc74b4b975013c97c3b5cc68489d8ac9b3970d
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/382495
Reviewed-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>

lib/bdev/virtio/rte_virtio/virtio_user/virtio_user_dev.c

@@ -194,6 +194,10 @@ virtio_user_dev_init(char *path, int queue_size)
 	uint64_t max_queues;
 
 	dev = calloc(1, sizeof(*dev));
+	if (dev == NULL) {
+		return NULL;
+	}
+
 	vdev = &dev->vdev;
 	vdev->is_hw = 0;