wireless: fix '!x & y' typo's

Fix priority mistakes similar to '!x & y'

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/libertas/wext.c b/drivers/net/wireless/libertas/wext.c
index 135116d..4dec5e5 100644
--- a/drivers/net/wireless/libertas/wext.c
+++ b/drivers/net/wireless/libertas/wext.c
@@ -1398,7 +1398,7 @@
 		index = adapter->wep_tx_keyidx;
 	}
 
-	if (!ext->ext_flags & IW_ENCODE_EXT_GROUP_KEY &&
+	if (!(ext->ext_flags & IW_ENCODE_EXT_GROUP_KEY) &&
 	    ext->alg != IW_ENCODE_ALG_WEP) {
 		if (index != 0 || adapter->mode != IW_MODE_INFRA)
 			goto out;