Unlike with struct protosw, several instances of struct ip6protosw

did not use C99-style sparse structure initialization, so remove
NULL assignments for now-removed pr_usrreq function pointers.

Reported by:	Chris Ruiz <yr.retarded at gmail.com>

sys/netinet6/in6_gif.c

@@ -78,7 +78,6 @@ extern  struct domain inet6domain;
 struct ip6protosw in6_gif_protosw =
 { SOCK_RAW,	&inet6domain,	0/* IPPROTO_IPV[46] */,	PR_ATOMIC|PR_ADDR,
   in6_gif_input, rip6_output,	0,		rip6_ctloutput,
-  0,
   0,		0,		0,		0,
   &rip6_usrreqs
 };

sys/netipsec/xform_ipip.c

@@ -673,7 +673,6 @@ static struct ip6protosw ipe6_protosw =
 { SOCK_RAW,	&inetdomain,	IPPROTO_IPV6,	PR_ATOMIC|PR_ADDR|PR_LASTHDR,
   ip4_input6,
 		0,	 	0,		rip_ctloutput,
-  0,
   0,		0,		0,		0,
   &rip_usrreqs
 };