test-aio: fix GSource-based timer test

The current test depends too much on the implementation of the AioContext
GSource.  Just iterate on the main loop until the callback has been invoked
the right number of times.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/test-aio.c

@@ -806,17 +806,16 @@ static void test_source_timer_schedule(void)
     g_usleep(1 * G_USEC_PER_SEC);
     g_assert_cmpint(data.n, ==, 0);
 
-    g_assert(g_main_context_iteration(NULL, false));
+    g_assert(g_main_context_iteration(NULL, true));
     g_assert_cmpint(data.n, ==, 1);
+    expiry += data.ns;
 
-    /* The comment above was not kidding when it said this wakes up itself */
-    do {
-        g_assert(g_main_context_iteration(NULL, true));
-    } while (qemu_clock_get_ns(data.clock_type) <= expiry);
-    g_usleep(1 * G_USEC_PER_SEC);
-    g_main_context_iteration(NULL, false);
+    while (data.n < 2) {
+        g_main_context_iteration(NULL, true);
+    }
 
     g_assert_cmpint(data.n, ==, 2);
+    g_assert(qemu_clock_get_ns(data.clock_type) > expiry);
 
     aio_set_fd_handler(ctx, pipefd[0], NULL, NULL, NULL);
     close(pipefd[0]);