Remove unnecessary locking of divcbinfo lock from div_output(): this has not
been required since FreeBSD 7.0 when the so_pcb pointer leading to inp was
guaranteed to be stable when a valid socket reference is held (as it is in
the output path).

MFC after:	1 week
Discussed with:	bz
Sponsored by:	Juniper Networks

Index: ip_divert.c
===================================================================
--- ip_divert.c	(revision 204797)
+++ ip_divert.c	(working copy)
@@ -385,7 +385,6 @@
 		struct inpcb *inp;
 
 		dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT;
-		INP_INFO_WLOCK(&V_divcbinfo);
 		inp = sotoinpcb(so);
 		INP_RLOCK(inp);
 		/*
@@ -396,7 +395,6 @@
 		     ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
 			error = EINVAL;
 			INP_RUNLOCK(inp);
-			INP_INFO_WUNLOCK(&V_divcbinfo);
 			m_freem(m);
 		} else {
 			/* Convert fields to host order for ip_output() */
@@ -437,7 +435,6 @@
 					error = ENOBUFS;
 			}
 			INP_RUNLOCK(inp);
-			INP_INFO_WUNLOCK(&V_divcbinfo);
 			if (error == ENOBUFS) {
 				m_freem(m);
 				return (error);