https://bugs.gentoo.org/958314

Fixes compilation error against musl-libc, like in https://github.com/md-raid-utilities/mdadm/issues/12#issuecomment-2119880626

Patch by Samuel Blythe <metroidhunter9000@proton.me>
--- a/ifrename.c
+++ b/ifrename.c
@@ -52,6 +52,12 @@
 
 #include "iwlib.h"		/* Wireless Tools library */
 
+/* Ensure GNU basename behavior for musl libc */
+#ifndef __GLIBC__
+#define basename(path) \
+       (strrchr((path),'/') ? strrchr((path),'/')+1 : (path))
+#endif
+
 // This would be cool, unfortunately...
 //#include <linux/ethtool.h>	/* Ethtool stuff -> struct ethtool_drvinfo */