iwlwifi: fix compile warning

Fixes following on big endian systems:
  CC [M]  drivers/net/wireless/iwlwifi/iwl-rx.o
  drivers/net/wireless/iwlwifi/iwl-rx.c: In function ‘iwl_rx_reply_rx’:
  drivers/net/wireless/iwlwifi/iwl-rx.c:1029: warning: integer overflow in
  expression

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reported-by: Marcel Holtmann <marcel@holtmann.org>
Tested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-3945.c

@@ -610,7 +610,7 @@ static void iwl3945_rx_reply_rx(struct iwl_priv *priv,
 	if (rx_status.band == IEEE80211_BAND_5GHZ)
 		rx_status.rate_idx -= IWL_FIRST_OFDM_RATE;
 
-	rx_status.antenna = le16_to_cpu(rx_hdr->phy_flags &
+	rx_status.antenna = (le16_to_cpu(rx_hdr->phy_flags) &
 					RX_RES_PHY_FLAGS_ANTENNA_MSK) >> 4;
 
 	/* set the preamble flag if appropriate */

drivers/net/wireless/iwlwifi/iwl-commands.h

@@ -1154,7 +1154,7 @@ struct iwl_wep_cmd {
 #define RX_RES_PHY_FLAGS_MOD_CCK_MSK		cpu_to_le16(1 << 1)
 #define RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK	cpu_to_le16(1 << 2)
 #define RX_RES_PHY_FLAGS_NARROW_BAND_MSK	cpu_to_le16(1 << 3)
-#define RX_RES_PHY_FLAGS_ANTENNA_MSK		cpu_to_le16(0xf0)
+#define RX_RES_PHY_FLAGS_ANTENNA_MSK		0xf0
 #define RX_RES_PHY_FLAGS_ANTENNA_POS		4
 
 #define RX_RES_STATUS_SEC_TYPE_MSK	(0x7 << 8)

drivers/net/wireless/iwlwifi/iwl-rx.c

@@ -1044,7 +1044,7 @@ void iwl_rx_reply_rx(struct iwl_priv *priv,
 	 * as a bitmask.
 	 */
 	rx_status.antenna =
-		le16_to_cpu(phy_res->phy_flags & RX_RES_PHY_FLAGS_ANTENNA_MSK)
+		(le16_to_cpu(phy_res->phy_flags) & RX_RES_PHY_FLAGS_ANTENNA_MSK)
 		>> RX_RES_PHY_FLAGS_ANTENNA_POS;
 
 	/* set the preamble flag if appropriate */