use asprintf() instead of Xasprintf()

All our supported platforms should have asprintf(), so we don't need
the Xserver's own implementation anymore.

It's one of two drivers blocking removal of this function form server ABI.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>

src/smi_video.c

@@ -53,6 +53,11 @@ authorization from the XFree86 Project and silicon Motion.
 #include "config.h"
 #endif
 
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <stdio.h>
+
 #include "smi.h"
 #include "smi_video.h"
 
@@ -519,7 +524,7 @@ SMI_AddEncoding(XF86VideoEncodingPtr enc, int i,
     norm_string = VideoNorms[norm].name;
     input_string = VideoInputs[input].name;
     snprintf(channel_string, sizeof(channel_string), "%d", channel);
-    if (Xasprintf(&name_string, "%s-%s-%s",
+    if (asprintf(&name_string, "%s-%s-%s",
                   norm_string, input_string, channel_string) < 0)
         LEAVE(-1);