Replace X-allocation functions with their C89 counterparts

The only remaining X-functions used in server are XNF*, the rest is converted to
plain alloc/calloc/realloc/free/strdup.

X* functions are still exported from server and x* macros are still defined in
header file, so both ABI and API are not affected by this change.

Signed-off-by: Mikhail Gusarov <dottedmag@dottedmag.net>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

fb/fboverlay.c

@@ -348,7 +348,7 @@ fbOverlayFinishScreenInit(ScreenPtr	pScreen,
     VisualID	defaultVisual;
     FbOverlayScrPrivPtr	pScrPriv;
 
-    pScrPriv = xalloc (sizeof (FbOverlayScrPrivRec));
+    pScrPriv = malloc(sizeof (FbOverlayScrPrivRec));
     if (!pScrPriv)
 	return FALSE;