qcacmn: Don't reset vdev id if stop spectral scan

Host gets spectral scan data after stopped spectral scan, then it
can't find out current vdev since vdev id is reset when stopping
spectral scan.

Change-Id: I082b784e998a7600c7f8ef14bf67b790942f3a5f
CRs-Fixed: 2779397

target_if/spectral/target_if_spectral.c

@@ -4546,7 +4546,6 @@ target_if_stop_spectral_scan(struct wlan_objmgr_pdev *pdev,
 
 	spectral->send_single_packet = 0;
 	spectral->sc_spectral_scan = 0;
-	spectral->vdev_id[smode] = WLAN_INVALID_VDEV_ID;
 
 	qdf_spin_unlock(&spectral->spectral_lock);