[media] coda: remove unnecessary peek at next destination buffer from coda_finish_decode

The return value of this call to v4l2_m2m_next_dst_buf() is never used.

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