[packages] iputils: fix ping6 compilation, the missing in6_pktinfo structure is protected by a _GNU_SOURCE feature macro

git-svn-id: svn://svn.openwrt.org/openwrt/packages@27108 3c298f89-4303-0410-b956-a3cf2f4a3e73

net/iputils/patches/011-ping6_use_gnu_source.patch

@@ -0,0 +1,11 @@
+--- a/ping6.c
++++ b/ping6.c
+@@ -66,6 +66,8 @@ char copyright[] =
+  *	More statistics could always be gathered.
+  *	This program has to run SUID to ROOT to access the ICMP socket.
+  */
++
++#define _GNU_SOURCE
+ #include "ping_common.h"
+ 
+ #include <linux/filter.h>