iwmc3200wifi: Fix test of unsigned in iwm_ntf_stop_resume_tx()

`queue' was unsigned so the test did not work.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Reviewed-by: Pavel Roskin <proski@gnu.org>
Acked-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwmc3200wifi/netdev.c b/drivers/net/wireless/iwmc3200wifi/netdev.c
index e4f0f87..c4c0d23 100644
--- a/drivers/net/wireless/iwmc3200wifi/netdev.c
+++ b/drivers/net/wireless/iwmc3200wifi/netdev.c
@@ -76,7 +76,7 @@
  */
 static const u16 iwm_1d_to_queue[8] = { 1, 0, 0, 1, 2, 2, 3, 3 };
 
-u16 iwm_tid_to_queue(u16 tid)
+int iwm_tid_to_queue(u16 tid)
 {
 	if (tid > IWM_UMAC_TID_NR - 2)
 		return -EINVAL;