staging: unisys: visorbus: add error handling textid_show

Don't just drop the error from visorchannel_read on the floor, report it.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/visorbus/visorchipset.c

@@ -205,12 +205,16 @@ static ssize_t textid_show(struct device *dev, struct device_attribute *attr,
 			   char *buf)
 {
 	u32 text_id = 0;
+	int err;
 
-	visorchannel_read
+	err = visorchannel_read
 			(chipset_dev->controlvm_channel,
 			 offsetof(struct spar_controlvm_channel_protocol,
 				  installation_text_id),
 			 &text_id, sizeof(u32));
+	if (err)
+		return err;
+
 	return sprintf(buf, "%i\n", text_id);
 }