nl80211: fix channel switch parsing

The nl80211 attribute NL80211_ATTR_CSA_C_OFF_BEACON should be nested
inside NL80211_ATTR_CSA_IES, but commit ee4bc9e75811d2c0cb5f2a2fc5b5
("nl80211: enable IBSS support for channel switch announcements")
added a check in the outer message attributes.

Fix channel switch calls by removing the erroneus condition.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
[reword commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -5713,9 +5713,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 
 	/* only important for AP, IBSS and mesh create IEs internally */
-	if (need_new_beacon &&
-	    (!info->attrs[NL80211_ATTR_CSA_IES] ||
-	     !info->attrs[NL80211_ATTR_CSA_C_OFF_BEACON]))
+	if (need_new_beacon && !info->attrs[NL80211_ATTR_CSA_IES])
 		return -EINVAL;
 
 	params.count = nla_get_u32(info->attrs[NL80211_ATTR_CH_SWITCH_COUNT]);