iwlagn: remove write-only variables

Updating the variables last_rx_rssi, last_tsf
and last_beacon_time needs a lot of code but
they are not actually used in iwlagn (only in
3945) so we can move them to the 3945 specific
data.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 8bf7c20..696e668 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -2956,12 +2956,8 @@
 		desc += sprintf(buff+desc,
 				"Bit Rate= %d Mb/s\n",
 				iwl_rates[lq_sta->last_txrate_idx].ieee >> 1);
-	desc += sprintf(buff+desc,
-			"Signal Level= %d dBm\tNoise Level= %d dBm\n",
-			priv->last_rx_rssi, priv->last_rx_noise);
-	desc += sprintf(buff+desc,
-			"Tsf= 0x%llx\tBeacon time= 0x%08X\n",
-			priv->last_tsf, priv->last_beacon_time);
+	desc += sprintf(buff+desc, "Noise Level= %d dBm\n",
+			priv->last_rx_noise);
 
 	ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 	return ret;