qcacld-3.0: HDD: Fix checkpatch return void warnings

Fix checkpatch return void warnings.
void function return statements are not generally useful.

Change-Id: I62f8720940a455345becdfa4043f1f5fdac9769d
CRs-Fixed: 2311614

core/hdd/src/wlan_hdd_power.c

@@ -1017,8 +1017,6 @@ flush_mc_list:
 		hdd_err("failed to flush mc list; status:%d", status);
 
 	hdd_exit();
-
-	return;
 }
 
 /**