staging: wilc1000: Modify null check routine

This patch removes the potential faults which may happen when unexpectedly
getting access to invalid pointer. Return error when the invalid memory is
accessed.
Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/host_interface.c

@@ -2384,8 +2384,10 @@ static s32 Handle_RcvdGnrlAsyncInfo(tstrWILC_WFIDrv *drvHandler,
 	s32 s32Err = 0;
 	tstrWILC_WFIDrv *pstrWFIDrv = (tstrWILC_WFIDrv *) drvHandler;
 
-	if (pstrWFIDrv == NULL)
+	if (!pstrWFIDrv) {
 		PRINT_ER("Driver handler is NULL\n");
+		return -ENODEV;
+	}
 	PRINT_D(GENERIC_DBG, "Current State = %d,Received state = %d\n", pstrWFIDrv->enuHostIFstate,
 		pstrRcvdGnrlAsyncInfo->pu8Buffer[7]);