util: introduce format_ifname()

src/basic/format-util.c

@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "format-util.h"
+#include "memory-util.h"
+
+char *format_ifname(int ifindex, char buf[static IF_NAMESIZE + 1]) {
+        /* Buffer is always cleared */
+        memzero(buf, IF_NAMESIZE + 1);
+        return if_indextoname(ifindex, buf);
+}