Allow compiling newly added if_index.c (at least on 2.4), missing __u32/__u16/__s32

libc/inet/netlinkaccess.h

@@ -21,6 +21,7 @@
 
 #include <features.h>
 #include <stdint.h>
+#include <linux/types.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>