When calculating the expected memory size for userspace, also take the

number of syncache entries into account for the surplus we add to account
for a possible increase of records in the re-entry window.

Discussed with:		jhb, silby
MFC after:		1 week

sys/netinet/tcp_subr.c

@@ -1022,7 +1022,7 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS)
 	if (req->oldptr == NULL) {
 		m = syncache_pcbcount();
 		n = V_tcbinfo.ipi_count;
-		n += imax(n / 8, 10);
+		n += imax((m + n) / 8, 10);
 		req->oldidx = 2 * (sizeof xig) +
 		    (m + n) * sizeof(struct xtcpcb);
 		return (0);