media: staging: rkisp1: fix test of return value of media_entity_get_fwnode_pad

media_entity_get_fwnode_pad returns negative value on error
and the pad numeber on success. Therefore change the error test
from 'if (ret)' to 'if (ret < 0)' .

Fixes: d65dd852 ("media: staging: rkisp1: add Rockchip ISP1 base driver")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/rkisp1/rkisp1-dev.c

@@ -128,7 +128,7 @@ static int rkisp1_create_links(struct rkisp1_device *rkisp1)
 
 		ret = media_entity_get_fwnode_pad(&sd->entity, sd->fwnode,
 						  MEDIA_PAD_FL_SOURCE);
-		if (ret) {
+		if (ret < 0) {
 			dev_err(sd->dev, "failed to find src pad for %s\n",
 				sd->name);
 			return ret;