[NET]: Transform skb_queue_len() binary tests into skb_queue_empty()

This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/hisax/isdnl1.c

@@ -279,7 +279,8 @@ BChannel_proc_xmt(struct BCState *bcs)
 	if (test_and_clear_bit(FLG_L1_PULL_REQ, &st->l1.Flags))
 		st->l1.l1l2(st, PH_PULL | CONFIRM, NULL);
 	if (!test_bit(BC_FLG_ACTIV, &bcs->Flag)) {
-		if (!test_bit(BC_FLG_BUSY, &bcs->Flag) && (!skb_queue_len(&bcs->squeue))) {
+		if (!test_bit(BC_FLG_BUSY, &bcs->Flag) &&
+		    skb_queue_empty(&bcs->squeue)) {
 			st->l2.l2l1(st, PH_DEACTIVATE | CONFIRM, NULL);
 		}
 	}