ath5k: fix regression which triggers an SME join upon assoc

This fixes a regression introduced by patch titled:

"atheros: define shared bssidmask setting"

The register for the BSSID was exchanged for the bssid mask register.
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/pcu.c

@@ -295,11 +295,11 @@ void ath5k_hw_set_associd(struct ath5k_hw *ah)
 	 */
 	ath5k_hw_reg_write(ah,
 			   get_unaligned_le32(common->curbssid),
-			   AR_BSSMSKL);
+			   AR5K_BSS_ID0);
 	ath5k_hw_reg_write(ah,
 			   get_unaligned_le16(common->curbssid + 4) |
 			   ((common->curaid & 0x3fff) << AR5K_BSS_ID1_AID_S),
-			   AR_BSSMSKU);
+			   AR5K_BSS_ID1);
 
 	if (common->curaid == 0) {
 		ath5k_hw_disable_pspoll(ah);