Use 0 timeout for command completion peek

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/io_u.c b/io_u.c
index 4f4865b..ab46cbe 100644
--- a/io_u.c
+++ b/io_u.c
@@ -526,6 +526,7 @@
 
 {
 	struct io_completion_data icd;
+	struct timespec *tvp = NULL;
 	int ret;
 
 	if (min_events > 0) {
@@ -534,9 +535,13 @@
 			td_verror(td, -ret);
 			return ret;
 		}
+	} else {
+		struct timespec ts = { .tv_sec = 0, .tv_nsec = 0, };
+
+		tvp = &ts;
 	}
 
-	ret = td_io_getevents(td, min_events, td->cur_depth, NULL);
+	ret = td_io_getevents(td, min_events, td->cur_depth, tvp);
 	if (ret < 0) {
 		td_verror(td, -ret);
 		return ret;