[media] m2m-deinterlace: remove dead code

As reported by smatch:
drivers/media/platform/m2m-deinterlace.c:1063 deinterlace_probe() info: ignoring unreachable code.

There's no need to call v4l2_m2m_release() here, as the last possible
failure in this code is to allocate the m2m struct.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>