Clear scan_res_handler on no-retry failure

Previously it was possible for wpa_s->scan_res_handler to remain set to
its old value in case wpa_drv_scan() failed and no retry for the scan
trigger was scheduled (i.e., when last_scan_req == MANUAL_SCAN_REQ).
This could result in getting stuck with the next connection attempt
after a failed "SCAN TYPE=ONLY" operation when wpa_s->scan_res_handler
was set to scan_only_handler().

Fix this by clearing wpa_s->scan_res_handler if wpa_drv_scan() fails and
no retry is scheduled.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/scan.c

@@ -208,6 +208,9 @@ static void wpas_trigger_scan_cb(struct wpa_radio_work *work, int deinit)
 			/* Restore scan_req since we will try to scan again */
 			wpa_s->scan_req = wpa_s->last_scan_req;
 			wpa_supplicant_req_scan(wpa_s, 1, 0);
+		} else if (wpa_s->scan_res_handler) {
+			/* Clear the scan_res_handler */
+			wpa_s->scan_res_handler = NULL;
 		}
 		return;
 	}