libpcap: Fix build when PACKAGECONFIG ipv6 is not enabled

Add patches provided upstream [1] by Fabio Berton to fix error:

> ./gencode.c: In function 'pcap_compile':
> ./gencode.c:693:8: error: 'compiler_state_t {aka struct _compiler_state}' has no member named 'ai'
>   cstate.ai = NULL;
>         ^
> ./gencode.c: In function 'gen_gateway':
> ./gencode.c:4914:13: error: 'cstate' undeclared (first use in this function)
>    bpf_error(cstate, "direction applied to 'gateway'");
>              ^

[1] https://github.com/the-tcpdump-group/libpcap/pull/541

Signed-off-by: Fabio Berton <fabio.berton@ossystems.com.br>
Tested-by: Zefir Kurtisi <zefir.kurtisi@neratec.com>

package/libs/libpcap/patches/001-Fix-compiler_state_t.ai-usage-when-INET6-is-not-defi.patch

@@ -0,0 +1,41 @@
+From 64aa033a061c43fc15c711f2490ae41d23b868c3 Mon Sep 17 00:00:00 2001
+From: Fabio Berton <fabio.berton@ossystems.com.br>
+Date: Thu, 17 Nov 2016 09:44:42 -0200
+Subject: [PATCH 1/2] Fix compiler_state_t.ai usage when INET6 is not defined
+Organization: O.S. Systems Software LTDA.
+
+Fix error:
+
+/
+| ../libpcap-1.8.1/gencode.c: In function 'pcap_compile':
+| ../libpcap-1.8.1/gencode.c:693:8: error: 'compiler_state_t
+| {aka struct _compiler_state}' has no member named 'ai'
+|   cstate.ai = NULL;
+\
+
+Upstream-Status: Submitted [1]
+
+[1] https://github.com/the-tcpdump-group/libpcap/pull/541
+
+Signed-off-by: Fabio Berton <fabio.berton@ossystems.com.br>
+---
+ gencode.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/gencode.c b/gencode.c
+index a887f27..e103c70 100644
+--- a/gencode.c
++++ b/gencode.c
+@@ -690,7 +690,9 @@ pcap_compile(pcap_t *p, struct bpf_program *program,
+ 	}
+ 	initchunks(&cstate);
+ 	cstate.no_optimize = 0;
++#ifdef INET6
+ 	cstate.ai = NULL;
++#endif
+ 	cstate.ic.root = NULL;
+ 	cstate.ic.cur_mark = 0;
+ 	cstate.bpf_pcap = p;
+-- 
+2.1.4
+

package/libs/libpcap/patches/002-Add-missing-compiler_state_t-parameter.patch

@@ -0,0 +1,67 @@
+From 50ec0a088d5924a8305b2d70dcba71b0942dee1a Mon Sep 17 00:00:00 2001
+From: Fabio Berton <fabio.berton@ossystems.com.br>
+Date: Thu, 17 Nov 2016 09:47:29 -0200
+Subject: [PATCH 2/2] Add missing compiler_state_t parameter
+Organization: O.S. Systems Software LTDA.
+
+Fix error:
+
+/
+|../libpcap-1.8.1/gencode.c: In function 'gen_gateway':
+|../libpcap-1.8.1/gencode.c:4914:13: error: 'cstate' undeclared
+| (first use in this function)
+|    bpf_error(cstate, "direction applied to 'gateway'");
+\
+
+Upstream-Status: Submitted [1]
+
+[1] https://github.com/the-tcpdump-group/libpcap/pull/541
+
+Signed-off-by: Fabio Berton <fabio.berton@ossystems.com.br>
+---
+ gencode.c | 15 ++++++++-------
+ 1 file changed, 8 insertions(+), 7 deletions(-)
+
+diff --git a/gencode.c b/gencode.c
+index e103c70..f07c0be 100644
+--- a/gencode.c
++++ b/gencode.c
+@@ -523,7 +523,7 @@ static struct block *gen_host6(compiler_state_t *, struct in6_addr *,
+     struct in6_addr *, int, int, int);
+ #endif
+ #ifndef INET6
+-static struct block *gen_gateway(const u_char *, bpf_u_int32 **, int, int);
++static struct block *gen_gateway(compiler_state_t *, const u_char *, bpf_u_int32 **, int, int);
+ #endif
+ static struct block *gen_ipfrag(compiler_state_t *);
+ static struct block *gen_portatom(compiler_state_t *, int, bpf_int32);
+@@ -4904,11 +4904,12 @@ gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
+ 
+ #ifndef INET6
+ static struct block *
+-gen_gateway(eaddr, alist, proto, dir)
+-	const u_char *eaddr;
+-	bpf_u_int32 **alist;
+-	int proto;
+-	int dir;
++gen_gateway(cstate, eaddr, alist, proto, dir)
++    compiler_state_t *cstate;
++    const u_char *eaddr;
++    bpf_u_int32 **alist;
++    int proto;
++    int dir;
+ {
+ 	struct block *b0, *b1, *tmp;
+ 
+@@ -6472,7 +6473,7 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
+ 		alist = pcap_nametoaddr(name);
+ 		if (alist == NULL || *alist == NULL)
+ 			bpf_error(cstate, "unknown host '%s'", name);
+-		b = gen_gateway(eaddr, alist, proto, dir);
++		b = gen_gateway(cstate, eaddr, alist, proto, dir);
+ 		free(eaddr);
+ 		return b;
+ #else
+-- 
+2.1.4
+