virtio_test: verify if virtqueue_kick() succeeded

Verify if a host kick succeeded by checking return value of virtqueue_kick().

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
index 059cb72..bdb71a2 100644
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -172,7 +172,8 @@
 							 GFP_ATOMIC);
 				if (likely(r == 0)) {
 					++started;
-					virtqueue_kick(vq->vq);
+					if (unlikely(!virtqueue_kick(vq->vq))
+						r = -1;
 				}
 			} else
 				r = -1;