iwlwifi: Fix HT compilation breakage caused by cfg80211 API for channels/bitrates patch

This patch fixes compilation breakage caused by 'cfg80211 API for
channels/bitrates' patch.
however it doesn't fix the driver's functional problems caused by that
patch.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
index f018ce4..a8223c4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -464,7 +464,7 @@
 	IWL_DEBUG_RATE("enter\n");
 
 	retries = tx_resp->retry_count;
-
+	/* FIXME : this is wrong */
 	first_index = &sband->bitrates[0] - tx_resp->control.tx_rate;
 	if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 		IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);