Move from memset to memset_s.

This adds the extra bounds checks and panics if there is a violation.

Change-Id: I9db3ca44be4f9c39964d912b57fe7b68e2792bc1
diff --git a/src/vm.c b/src/vm.c
index a58886e..d1fb5bb 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -36,7 +36,7 @@
 
 	vm = &vms[vm_count];
 
-	memset(vm, 0, sizeof(*vm));
+	memset_s(vm, sizeof(*vm), 0, sizeof(*vm));
 
 	list_init(&vm->mailbox.waiter_list);
 	list_init(&vm->mailbox.ready_list);