qcacld-3.0: set global context to NULL only when all the cleanup is completed

In cds_deint, cds global context is set to NULL and then cleanup handlers of
memory/timer/nbuf manager's are invoked. During the cleanup these handlers
use QDF_TRACE to print the cleanup information which internally tries to
get the global context resulting in not clean unload of driver.

To migitate the issue set global context to NULL once the clean up of
all handlers is completed cleanly.

Change-Id: Ic58962dfd543020d79cabd7b646e483c4f7961f2
CRs-Fixed: 1067340

core/cds/src/cds_api.c

@@ -117,14 +117,13 @@ void cds_deinit(void)
 	if (gp_cds_context == NULL)
 		return;
 
+	qdf_mc_timer_manager_exit();
+	qdf_mem_exit();
+
 	gp_cds_context->qdf_ctx = NULL;
 	gp_cds_context = NULL;
 
 	qdf_mem_zero(&g_cds_context, sizeof(g_cds_context));
-
-	qdf_mc_timer_manager_exit();
-	qdf_mem_exit();
-
 	return;
 }