iwlwifi: fix antenna bitmask

The device only supports a maximum of three
antennas, and only three bits are used, the
fourth bit is the A-MPDU indicator.

The only consequence of this is reporting
invalid information in radiotap, so this
isn't an important change.
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

drivers/net/wireless/iwlwifi/dvm/commands.h

@@ -1055,7 +1055,7 @@ 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		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)