media: seco-cec: Add a missing 'release_region()' in an error handling path

At the beginning of the probe function, we have a call to
'request_muxed_region(BRA_SMB_BASE_ADDR, 7, "CEC00001")()'

A corresponding 'release_region()' is performed in the remove function but
is lacking in the error handling path.

Add it.

Fixes: b03c2fb9

 ("media: add SECO cec driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>