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>

hw/xquartz/pseudoramiX.c

@@ -94,7 +94,7 @@ PseudoramiXAddScreen(int x, int y, int w, int h)
 
     if (pseudoramiXNumScreens == pseudoramiXScreensAllocated) {
         pseudoramiXScreensAllocated += pseudoramiXScreensAllocated + 1;
-        pseudoramiXScreens = xrealloc(pseudoramiXScreens,
+        pseudoramiXScreens = realloc(pseudoramiXScreens,
                                       pseudoramiXScreensAllocated *
                                       sizeof(PseudoramiXScreenRec));
     }