iwlegacy: fix antenna bitmask

This patch is based on "iwlwifi: fix antenna bitmask".
(362b0563)

Like the new iwlagn devices, the old 4965N device only
supports a maximum of three antennas. Hence only three
bits are used, the fourth bit is likely the A-MPDU
indicator.

Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlegacy/commands.h

@@ -1134,7 +1134,7 @@ struct il_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		0xf0
+#define RX_RES_PHY_FLAGS_ANTENNA_MSK		0x70
 #define RX_RES_PHY_FLAGS_ANTENNA_POS		4
 
 #define RX_RES_STATUS_SEC_TYPE_MSK	(0x7 << 8)