virtio-mem: drop unnecessary initialization

rc is initialized to -ENIVAL but that's never used. Drop it.

Fixes: 5f1f79bb ("virtio-mem: Paravirtualized memory hotplug")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>

drivers/virtio/virtio_mem.c

@@ -1768,7 +1768,7 @@ static void virtio_mem_delete_resource(struct virtio_mem *vm)
 static int virtio_mem_probe(struct virtio_device *vdev)
 {
 	struct virtio_mem *vm;
-	int rc = -EINVAL;
+	int rc;
 
 	BUILD_BUG_ON(sizeof(struct virtio_mem_req) != 24);
 	BUILD_BUG_ON(sizeof(struct virtio_mem_resp) != 10);