Rename invocations of frame_create that were missed by ee7fefcf

For some reason it not only compiled with different parameters but the
method succeeded and just failed later.
diff --git a/clients/gears.c b/clients/gears.c
index 30f4e68..93a86b4 100644
--- a/clients/gears.c
+++ b/clients/gears.c
@@ -404,7 +404,7 @@
 	gears = zalloc(sizeof *gears);
 	gears->d = display;
 	gears->window = window_create(display);
-	gears->widget = frame_create(gears->window, gears);
+	gears->widget = window_frame_create(gears->window, gears);
 	window_set_title(gears->window, "Wayland Gears");
 
 	gears->display = display_get_egl_display(gears->d);