nl80211: Fix set_key regression with some drivers

Commit dbd2fd65 added a mechanism for
user space to indicate whether a default key is being configured for
only unicast or only multicast frames instead of all frames. This
commit added a driver capability flag for indicating whether separate
default keys are supported and validation of the set_key command based
on that capability.

However, this single capability flag is not enough to cover possible
difference based on mode (AP/IBSS/STA) and the way this change was
introduced resulted in a regression with drivers that do not indicate
the new capability (i.e.., more or less any non-mac80211 driver using
cfg80211) when using a recent wpa_supplicant snapshot.

Fix the regression by removing the new check which is not strictly
speaking needed. The new separate default key functionality is needed
only for RSN IBSS which has a separate capability indication.

Cc: stable@kernel.org
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/nl80211.c

@@ -1682,14 +1682,6 @@ static int nl80211_set_key(struct sk_buff *skb, struct genl_info *info)
 		if (err)
 			goto out;
 
-		if (!(rdev->wiphy.flags &
-				WIPHY_FLAG_SUPPORTS_SEPARATE_DEFAULT_KEYS)) {
-			if (!key.def_uni || !key.def_multi) {
-				err = -EOPNOTSUPP;
-				goto out;
-			}
-		}
-
 		err = rdev->ops->set_default_key(&rdev->wiphy, dev, key.idx,
 						 key.def_uni, key.def_multi);