Update a comment which to my reading had been misplaced in rev. 1.12

already (but probably had been way above as the code was there twice)
and describe what was last changed in rev. 1.199 there (which now is
in sync with in6_src.c r184096).

Pointed at by:	mlaier
MFC after:	2 mmonths

sys/netinet/in_pcb.c

@@ -458,8 +458,9 @@ in_pcbbind_setup(struct inpcb *inp, struct sockaddr *nam, in_addr_t *laddrp,
 		if (pcbinfo != &V_udbinfo)
 			V_ipport_tcpallocs++;
 		/*
-		 * Simple check to ensure all ports are not used up causing
-		 * a deadlock here.
+		 * Instead of having two loops further down counting up or down
+		 * make sure that first is always <= last and go with only one
+		 * code path implementing all logic.
 		 */
 		if (first > last) {
 			aux = first;