media: ov5693: Simplify an error message

dev_err_probe() already display the error code. There is no need to
duplicate it explicitly in the error message.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>