[media] gs1662: drop kfree for memory allocated with devm_kzalloc

It's not necessary to free memory allocated with devm_kzalloc
and using kfree leads to a double free.

Fixes: 7aae6e2d ("[media] Add GS1662 driver, a video serializer")

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>