Fix build with CFLAGS="-std=c11 -D_GNU_SOURCE"

src/fcxml.c

@@ -22,9 +22,6 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-#ifdef _GNU_SOURCE
-#undef _GNU_SOURCE /* To use the POSIX version of strerror_r */
-#endif
 #include <string.h>
 #include "fcint.h"
 #include <fcntl.h>
@@ -3474,8 +3471,7 @@ _FcConfigParse (FcConfig	*config,
 	    char ebuf[BUFSIZ+1];
 
 #if HAVE_STRERROR_R
-	    int x FC_UNUSED;
-	    x = strerror_r (errno_, ebuf, BUFSIZ); /* make sure we use the POSIX version of strerror_r */
+	    strerror_r (errno_, ebuf, BUFSIZ);
 #elif HAVE_STRERROR
 	    char *tmp = strerror (errno_);
 	    size_t len = strlen (tmp);