b43: Fix sparse warning in hw-tkip code

This fixes a sparse warning in the hardware-TKIP code:

drivers/net/wireless/b43/xmit.c:272:18: warning: incorrect type in assignment (different base types)
drivers/net/wireless/b43/xmit.c:272:18:    expected unsigned short [unsigned] [short] <noident>
drivers/net/wireless/b43/xmit.c:272:18:    got restricted unsigned short [usertype] <noident>

The code should work correctly with and without this patch applied.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/xmit.c

@@ -267,11 +267,11 @@ int b43_generate_txhdr(struct b43_wldev *dev,
 			 */
 			ieee80211_get_tkip_key(info->control.hw_key, skb_frag,
 					IEEE80211_TKIP_P1_KEY, (u8*)phase1key);
-			/* phase1key is in host endian */
-			for (i = 0; i < 5; i++)
-				phase1key[i] = cpu_to_le16(phase1key[i]);
-
-			memcpy(txhdr->iv, phase1key, 10);
+			/* phase1key is in host endian. Copy to little-endian txhdr->iv. */
+			for (i = 0; i < 5; i++) {
+				txhdr->iv[i * 2 + 0] = phase1key[i];
+				txhdr->iv[i * 2 + 1] = phase1key[i] >> 8;
+			}
 			/* iv16 */
 			memcpy(txhdr->iv + 10, ((u8 *) wlhdr) + wlhdr_len, 3);
 		} else {