media: atomisp: Remove redundant NULL check

./drivers/staging/media/atomisp/pci/isp/kernels/sdis/sdis_1.0/ia_css_sdis.host.c:390:2-8: WARNING: NULL check before some freeing functions is not needed.

Link: https://lore.kernel.org/linux-media/20201225084524.64839-1-vulab@iscas.ac.cn


Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>