b43: Fix hardware key index handling

This fixes the hardware encryption keys index and array size handling.

Thanks to Gregor Kowski for reporting this issue.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index 5b85e7d..5280ebc 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -237,7 +237,7 @@
 		int wlhdr_len;
 		size_t iv_len;
 
-		B43_WARN_ON(key_idx >= dev->max_nr_keys);
+		B43_WARN_ON(key_idx >= ARRAY_SIZE(dev->key));
 		key = &(dev->key[key_idx]);
 
 		if (unlikely(!key->keyconf)) {
@@ -578,7 +578,7 @@
 		 * key index, but the ucode passed it slightly different.
 		 */
 		keyidx = b43_kidx_to_raw(dev, keyidx);
-		B43_WARN_ON(keyidx >= dev->max_nr_keys);
+		B43_WARN_ON(keyidx >= ARRAY_SIZE(dev->key));
 
 		if (dev->key[keyidx].algorithm != B43_SEC_ALGO_NONE) {
 			wlhdr_len = ieee80211_hdrlen(fctl);