media: atomisp: move up sanity checks

The sanity checks were done too late, so move them up.

This fixes this smatch warning:

drivers/staging/media/atomisp/pci/sh_css_firmware.c:247 sh_css_load_firmware() warn: variable dereferenced before check 'fw_data' (see line 237)

Link: https://lore.kernel.org/r/20230524121150.435736-9-hverkuil-cisco@xs4all.nl



Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>