posixaio: Missing memset()

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/engines/posixaio.c b/engines/posixaio.c
index 9514175..ddc75d1 100644
--- a/engines/posixaio.c
+++ b/engines/posixaio.c
@@ -93,7 +93,7 @@
 		have_timeout = 1;
 
 	r = 0;
-	suspend_list[0] = NULL;
+	memset(suspend_list, 0, sizeof(*suspend_list));
 restart:
 	list_for_each(entry, &td->io_u_busylist) {
 		struct io_u *io_u = list_entry(entry, struct io_u, list);