ANDROID: CRC ABI fixups in ip.h and ipv6.h

In commit 6e9334436d ("net: use struct_group to copy ip/ipv6 header
addresses"), struct_group() is added to some structures to resolve a
build warning.  This changes the CRC of a number of networking
functions, without changing any actual structure sizes or interactions.
To resolve this, use __GENKSYMS__ #ifdef hack to preserve the Android
kernel CRC abi.

Bug: 161946584
Fixes: 6e9334436d ("net: use struct_group to copy ip/ipv6 header addresses")
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ia70eb3aa41316fbced713c99c85ddaeccec2ffec

include/uapi/linux/ip.h

@@ -100,10 +100,14 @@ struct iphdr {
 	__u8	ttl;
 	__u8	protocol;
 	__sum16	check;
+#ifndef __GENKSYMS__
 	__struct_group(/* no tag */, addrs, /* no attrs */,
+#endif
 		__be32	saddr;
 		__be32	daddr;
+#ifndef __GENKSYMS__
 	);
+#endif
 	/*The options start here. */
 };
 

include/uapi/linux/ipv6.h

@@ -130,10 +130,14 @@ struct ipv6hdr {
 	__u8			nexthdr;
 	__u8			hop_limit;
 
+#ifndef __GENKSYMS__
 	__struct_group(/* no tag */, addrs, /* no attrs */,
+#endif
 		struct	in6_addr	saddr;
 		struct	in6_addr	daddr;
+#ifndef __GENKSYMS__
 	);
+#endif
 };