staging: wilc1000: use sizeof(*wdev) to allocate memory in wilc_wfi_cfg_alloc()

Fix below reported checkpatch issues in wilc_wfi_cfg_alloc().
kzalloc(sizeof(*wdev)...) over kzalloc(sizeof(struct wireless_dev)
Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/wilc_wfi_cfgoperations.c

@@ -2184,7 +2184,7 @@ static struct wireless_dev *wilc_wfi_cfg_alloc(void)
 {
 	struct wireless_dev *wdev;
 
-	wdev = kzalloc(sizeof(struct wireless_dev), GFP_KERNEL);
+	wdev = kzalloc(sizeof(*wdev), GFP_KERNEL);
 	if (!wdev)
 		goto _fail_;