Fix not to update the iterator element, instead use list_del to remove
entry from the list.

This fixes the following coccinelle and static checker warning:
sound/soc/codecs/hdac_hdmi.c:1884:2-21:iterator with update on line
1885
sound/soc/codecs/hdac_hdmi.c:2011 hdac_hdmi_dev_remove()
	error: potential NULL dereference 'port'.

Fixes: e0e5d3e5('ASoC: hdac_hdmi: Add support for multiple ports to a PCM')
Reported-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJeeja KP <jeeja.kp@intel.com>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Signed-off-by: NMark Brown <broonie@kernel.org>