ath9k: Maintain rate table choice after association

A scan run after association would change sc_curmode which is
used to get the current rate table. This patch fixes it
by removing sc_curmode and setting the rate table in usage in cur_rate_table
on association.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/beacon.c b/drivers/net/wireless/ath9k/beacon.c
index d874223..9e5c0c0 100644
--- a/drivers/net/wireless/ath9k/beacon.c
+++ b/drivers/net/wireless/ath9k/beacon.c
@@ -106,7 +106,7 @@
 	 * XXX everything at min xmit rate
 	 */
 	rix = 0;
-	rt = sc->hw_rate_table[sc->sc_curmode];
+	rt = sc->cur_rate_table;
 	rate = rt->info[rix].ratecode;
 	if (sc->sc_flags & SC_OP_PREAMBLE_SHORT)
 		rate |= rt->info[rix].short_preamble;