Staging: asus_oled: fix build warnings

This fixes some build warnings in the asus_oled driver.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/asus_oled/asus_oled.c b/drivers/staging/asus_oled/asus_oled.c
index 04dde4b..9270f5d 100644
--- a/drivers/staging/asus_oled/asus_oled.c
+++ b/drivers/staging/asus_oled/asus_oled.c
@@ -516,7 +516,7 @@
 	max_offs = odev->width * odev->height;
 
 	while (offs < count && odev->buf_offs < max_offs) {
-		int ret;
+		int ret = 0;
 
 		if (buf[offs] == '1' || buf[offs] == '#') {
 			ret = append_values(odev, 1, 1);