perf: fix strerror_r override detection, apparently part of tools/ relies on non-GNU behavior

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 48221

package/devel/perf/musl-include/string.h

@@ -0,0 +1,18 @@
+#ifndef __MUSL_COMPAT_STRING_H
+#define __MUSL_COMPAT_STRING_H
+
+#include_next <string.h>
+
+/* Change XSI compliant version into GNU extension hackery */
+static inline char *
+gnu_strerror_r(int err, char *buf, size_t buflen)
+{
+	if (strerror_r(err, buf, buflen))
+		return NULL;
+	return buf;
+}
+#ifdef _GNU_SOURCE
+#define strerror_r gnu_strerror_r
+#endif
+
+#endif