nl80211: check NL80211_ATTR_SCHED_SCAN_INTERVAL only once

The presence of the NL80211_ATTR_SCHED_SCAN_INTERVAL attribute was
checked in nl80211_parse_sched_scan() and
nl80211_parse_sched_scan_plans() which might be a bit redundant
so removing one.
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/nl80211.c

@@ -6775,13 +6775,10 @@ nl80211_parse_sched_scan_plans(struct wiphy *wiphy, int n_plans,
 
 		/*
 		 * If scan plans are not specified,
-		 * %NL80211_ATTR_SCHED_SCAN_INTERVAL must be specified. In this
+		 * %NL80211_ATTR_SCHED_SCAN_INTERVAL will be specified. In this
 		 * case one scan plan will be set with the specified scan
 		 * interval and infinite number of iterations.
 		 */
-		if (!attrs[NL80211_ATTR_SCHED_SCAN_INTERVAL])
-			return -EINVAL;
-
 		interval = nla_get_u32(attrs[NL80211_ATTR_SCHED_SCAN_INTERVAL]);
 		if (!interval)
 			return -EINVAL;