iwlegacy: print how long queue was actually stuck

Every now and then, after resuming from suspend, the iwlegacy driver
prints
    iwl4965 0000:03:00.0: Queue 2 stuck for 2000 ms.
    iwl4965 0000:03:00.0: On demand firmware reload

I have no idea what causes these errors. But the code currently uses
wd_timeout in the first error. wd_timeout will generally be set at
IL_DEF_WD_TIMEOUT (ie, 2000). Perhaps printing for how long the queue
was actually stuck can clarify the cause of these errors.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlegacy/common.c

@@ -4717,10 +4717,11 @@ il_check_stuck_queue(struct il_priv *il, int cnt)
 	struct il_tx_queue *txq = &il->txq[cnt];
 	struct il_queue *q = &txq->q;
 	unsigned long timeout;
+	unsigned long now = jiffies;
 	int ret;
 
 	if (q->read_ptr == q->write_ptr) {
-		txq->time_stamp = jiffies;
+		txq->time_stamp = now;
 		return 0;
 	}
 
@@ -4728,9 +4729,9 @@ il_check_stuck_queue(struct il_priv *il, int cnt)
 	    txq->time_stamp +
 	    msecs_to_jiffies(il->cfg->wd_timeout);
 
-	if (time_after(jiffies, timeout)) {
+	if (time_after(now, timeout)) {
 		IL_ERR("Queue %d stuck for %u ms.\n", q->id,
-		       il->cfg->wd_timeout);
+		       jiffies_to_msecs(now - txq->time_stamp));
 		ret = il_force_reset(il, false);
 		return (ret == -EAGAIN) ? 0 : 1;
 	}