modesetting: fix glamor ifdef

Add a missing ifdef needed for --disable-glamor.

Signed-off-by: Mihail Konev <k.mvc@ya.ru>
Reviewed-by: Jon Turney <jon.turney@dronecode.org.uk>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

hw/xfree86/drivers/modesetting/driver.c

@@ -594,6 +594,7 @@ redisplay_dirty(ScreenPtr screen, PixmapDirtyUpdatePtr dirty, int *timeout)
     PixmapSyncDirtyHelper(dirty);
 
     if (!screen->isGPU) {
+#ifdef GLAMOR
         /*
          * When copying from the master framebuffer to the shared pixmap,
          * we must ensure the copy is complete before the slave starts a
@@ -602,6 +603,7 @@ redisplay_dirty(ScreenPtr screen, PixmapDirtyUpdatePtr dirty, int *timeout)
          */
         if (ms->drmmode.glamor)
             glamor_finish(screen);
+#endif
         /* Ensure the slave processes the damage immediately */
         if (timeout)
             *timeout = 0;