[media] coda: do not call v4l2_m2m_job_finish from .job_abort

If we just declare the job finished here while the CODA is still
running, the call to v4l2_m2m_ctx_release in coda_release, which
is supposed to wait for a running job to finish, will return
immediately and free memory that the CODA is still using.
Just set the 'aborting' flag and let coda_irq_handler deal with it.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>