qcacmn: Change return type in case of simultaneous scan

Currently the driver returns EINVAL, instead of EBUSY if
the driver encounters a case of simlutaneuos scan, and
DBS scan is disabled for user space, and thus it may lead
to failure of OBSS scan, which can further lead to SAP
fail.

Fix is to return EBUSY intead of EINVAL, so that hostapd
can try to get the scan module perform a scan, which can
increase the probablity of SAP bringup.

Change-Id: I798e3d1ad0f62a5240603b4344963cb3ee637c13
CRs-Fixed: 2403499

os_if/linux/scan/src/wlan_cfg80211_scan.c

@@ -1315,7 +1315,7 @@ int wlan_cfg80211_scan(struct wlan_objmgr_vdev *vdev,
 	if (!wlan_cfg80211_allow_simultaneous_scan(psoc) &&
 	    !qdf_list_empty(&osif_priv->osif_scan->scan_req_q)) {
 		cfg80211_err("Simultaneous scan disabled, reject scan");
-		return -EINVAL;
+		return -EBUSY;
 	}
 
 	req = qdf_mem_malloc(sizeof(*req));