st/glx: use strdup() instead of _mesa_strdup()

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/gallium/state_trackers/glx/xlib/glx_api.c

@@ -34,6 +34,7 @@
 #include "GL/glx.h"
 
 #include <stdio.h>
+#include <string.h>
 #include <X11/Xmd.h>
 #include <GL/glxproto.h>
 
@@ -644,7 +645,7 @@ register_with_display(Display *dpy)
       ext = dpy->ext_procs;  /* new extension is at head of list */
       assert(c->extension == ext->codes.extension);
       (void) c;
-      ext->name = _mesa_strdup(extName);
+      ext->name = strdup(extName);
       ext->close_display = close_display_callback;
    }
 }