staging: slicoss: fail out if we dont have a valid firmware file

fail instead calling request_firmware with filename as a null string
and return -ENOENT

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/slicoss/slicoss.c

@@ -593,8 +593,7 @@ static int slic_card_download(struct adapter *adapter)
 		file = "slicoss/gbdownload.sys";
 		break;
 	default:
-		ASSERT(0);
-		break;
+		return -ENOENT;
 	}
 	ret = request_firmware(&fw, file, &adapter->pcidev->dev);
 	if (ret) {