qcacld-3.0: Remove unused variable and avoid compilation fail

This change removes unused variable "mac" in function -
sme_set_auto_shutdown_timer and avoid compilation fail.

Change-Id: I4a3ae1ea0deb62d6d43845330162dc8a24b8ab62
CRs-Fixed: 2890806

core/sme/src/common/sme_api.c

@@ -8222,7 +8222,6 @@ QDF_STATUS sme_set_auto_shutdown_timer(mac_handle_t mac_handle,
 {
 	QDF_STATUS status = QDF_STATUS_SUCCESS;
 	QDF_STATUS qdf_status = QDF_STATUS_SUCCESS;
-	struct mac_context *mac = MAC_CONTEXT(mac_handle);
 	struct auto_shutdown_cmd *auto_sh_cmd;
 	struct scheduler_msg message = {0};