RRScanOldConfig cannot use RRFirstOutput before output is configured.

RRFirstOutput returns the first active output, which won't be set until
after RRScanOldConfig is finished running. Instead, just use the first
output (which is the only output present with an old driver, after all).

randr/rrinfo.c

@@ -104,7 +104,7 @@ RRScanOldConfig (ScreenPtr pScreen, Rotation rotations)
 #endif
     }
 
-    output = RRFirstOutput (pScreen);
+    output = pScrPriv->outputs[0];
     if (!output)
 	return;
     crtc = pScrPriv->crtcs[0];