glamor: Fixed one linking error.

As current glamor implementation depends on the glx library in the
mesa package which is conflict with the version in xorg. We have to
--disable-glx when build Xephyr. But this leads to the linking error
here. We comment out the calling to ephyrHijackGLXExtension() now.
Need revisit latter.

hw/kdrive/ephyr/ephyr.c

@@ -669,7 +669,9 @@ ephyrInitScreen (ScreenPtr pScreen)
   }
   if (!ephyrNoDRI) {
     ephyrDRIExtensionInit (pScreen) ;
+#if 0
     ephyrHijackGLXExtension () ;
+#endif
   }
 #endif