media: meson/ge2d: set ret to -ENOMEM

Fix this smatch warning:

drivers/media/platform/meson/ge2d/ge2d.c:991 ge2d_probe() warn: missing error code 'ret'

when video_device_alloc() returns NULL.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>