qcacld-3.0: Return success for sched_scan_stop

Presently in the driver, the function __cfg80211_stop_sched_scan
clears rdev->sched_scan_req only when the sched_scan_stop returns
success. If it returns a failure, then its next invocation due to the
clean up of the second interface will have the dev pointer corresponding
to the first one leading to incorrect memory access.

To resolve this issue, return 0 for stop_sched_scan irrespective of the
return status.

Change-Id: I129e3e9c6d9f6a688d0aa97be120ba9731e8df37
CRs-Fixed: 2623160

core/hdd/src/wlan_hdd_scan.c

@@ -1489,7 +1489,16 @@ int wlan_hdd_cfg80211_sched_scan_stop(struct wiphy *wiphy,
 
 	osif_vdev_sync_op_stop(vdev_sync);
 
-	return errno;
+	/* The return 0 is intentional. We observed a crash due to a return of
+	 * failure in sched_scan_stop , especially for a case where the unload
+	 * of the happens at the same time. The function
+	 * __cfg80211_stop_sched_scan was clearing rdev->sched_scan_req only
+	 * when the sched_scan_stop returns success. If it returns a failure ,
+	 * then its next invocation due to the clean up of the second interface
+	 * will have the dev pointer corresponding to the first one leading to
+	 * a crash.
+	 */
+	return 0;
 }
 #else
 int wlan_hdd_cfg80211_sched_scan_stop(struct wiphy *wiphy,
@@ -1507,7 +1516,16 @@ int wlan_hdd_cfg80211_sched_scan_stop(struct wiphy *wiphy,
 
 	osif_vdev_sync_op_stop(vdev_sync);
 
-	return errno;
+	/* The return 0 is intentional. We observed a crash due to a return of
+	 * failure in sched_scan_stop , especially for a case where the unload
+	 * of the happens at the same time. The function
+	 * __cfg80211_stop_sched_scan was clearing rdev->sched_scan_req only
+	 * when the sched_scan_stop returns success. If it returns a failure ,
+	 * then its next invocation due to the clean up of the second interface
+	 * will have the dev pointer corresponding to the first one leading to
+	 * a crash.
+	 */
+	return 0;
 }
 #endif /* KERNEL_VERSION(4, 12, 0) */
 #endif /*FEATURE_WLAN_SCAN_PNO */