media: omap4iss: return error code when omap4iss_get() failed

If omap4iss_get() failed, it need return error code in iss_probe().

Fixes: 59f0ad807681 ("[media] v4l: omap4iss: Add support for OMAP4...")
Reported-by: Hulk Robot <[e-mail]>
Signed-off-by: Yang Yingliang <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/staging/media/omap4iss/iss.c

···
 	if (ret < 0)
 		goto error;
 
-	if (!omap4iss_get(iss))
+	if (!omap4iss_get(iss)) {
+		ret = -EINVAL;
 		goto error;
+	}
 
 	ret = iss_reset(iss);
 	if (ret < 0)