[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/s390/net/claw.c

@@ -428,7 +428,7 @@ claw_pack_skb(struct claw_privbk *privptr)
 	new_skb = NULL;		/* assume no dice */
 	pkt_cnt = 0;
 	CLAW_DBF_TEXT(4,trace,"PackSKBe");
-	if (skb_queue_len(&p_ch->collect_queue) > 0) {
+	if (!skb_queue_empty(&p_ch->collect_queue)) {
 	/* some data */
 		held_skb = skb_dequeue(&p_ch->collect_queue);
 		if (p_env->packing != DO_PACKED)
@@ -1254,7 +1254,7 @@ claw_write_next ( struct chbk * p_ch )
 	privptr = (struct claw_privbk *) dev->priv;
         claw_free_wrt_buf( dev );
 	if ((privptr->write_free_count > 0) &&
-	    (skb_queue_len(&p_ch->collect_queue) > 0)) {
+	    !skb_queue_empty(&p_ch->collect_queue)) {
 	  	pk_skb = claw_pack_skb(privptr);
 		while (pk_skb != NULL) {
 			rc = claw_hw_tx( pk_skb, dev,1);

drivers/s390/net/ctctty.c

@@ -156,7 +156,7 @@ ctc_tty_readmodem(ctc_tty_info *info)
 					skb_queue_head(&info->rx_queue, skb);
 				else {
 					kfree_skb(skb);
-					ret = skb_queue_len(&info->rx_queue);
+					ret = !skb_queue_empty(&info->rx_queue);
 				}
 			}
 		}
@@ -530,7 +530,7 @@ ctc_tty_write(struct tty_struct *tty, const u_char * buf, int count)
 		total += c;
 		count -= c;
 	}
-	if (skb_queue_len(&info->tx_queue)) {
+	if (!skb_queue_empty(&info->tx_queue)) {
 		info->lsr &= ~UART_LSR_TEMT;
 		tasklet_schedule(&info->tasklet);
 	}
@@ -594,7 +594,7 @@ ctc_tty_flush_chars(struct tty_struct *tty)
 		return;
 	if (ctc_tty_paranoia_check(info, tty->name, "ctc_tty_flush_chars"))
 		return;
-	if (tty->stopped || tty->hw_stopped || (!skb_queue_len(&info->tx_queue)))
+	if (tty->stopped || tty->hw_stopped || skb_queue_empty(&info->tx_queue))
 		return;
 	tasklet_schedule(&info->tasklet);
 }