inpcb: use correct mask in in6_pcblookup_lbgroup()

There is no visible bug fixed as in current tree masks are the same.

Fixes:	6883b120c5

sys/netinet6/in6_pcb.c

@@ -910,7 +910,7 @@ in6_pcblookup_lbgroup(const struct inpcbinfo *pcbinfo,
 	NET_EPOCH_ASSERT();
 
 	hdr = &pcbinfo->ipi_lbgrouphashbase[
-	    INP_PCBPORTHASH(lport, pcbinfo->ipi_porthashmask)];
+	    INP_PCBPORTHASH(lport, pcbinfo->ipi_lbgrouphashmask)];
 
 	/*
 	 * Search for an LB group match based on the following criteria: