qcacld-3.0: Return -EAGAIN for idle shutdown if rmmod is in progress

If rmmod is in progress, return -EAGAIN for idle shutdown such that
cnss driver does not power off the soc and rmmod can succeed.

Change-Id: I91845da41bb666792a55aa3d446058025ce0fadb
CRs-Fixed: 2751194

core/hdd/src/wlan_hdd_main.c

@@ -11218,6 +11218,7 @@ static int __hdd_psoc_idle_shutdown(struct hdd_context *hdd_ctx)
 	errno = osif_psoc_sync_trans_start(hdd_ctx->parent_dev, &psoc_sync);
 	if (errno) {
 		hdd_info("psoc busy, abort idle shutdown; errno:%d", errno);
+		errno = -EAGAIN;
 		goto exit;
 	}