iwlagn: move iwlagn_stop_device to transport layer

Since iwlagn_stop_device was the only caller to the rx_stop / tx_stop,
these two don't need to be API any more.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-ucode.c b/drivers/net/wireless/iwlwifi/iwl-agn-ucode.c
index 06304a6..c15a1f7 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-ucode.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-ucode.c
@@ -707,6 +707,6 @@
 	iwlagn_remove_notification(priv, &calib_wait);
  out:
 	/* Whatever happened, stop the device */
-	iwlagn_stop_device(priv);
+	trans_stop_device(priv);
 	return ret;
 }