media: atomisp: Simplify v4l2_fh_open() error handling

v4l2_fh_open() can only fail with -ENOMEM and as a generic rule drivers
do not log their own errors for -ENOMEM since the kernel will already
have complained loudly about this before the -ENOMEM return.

Remove the unnecessary error logging from atomisp_open().

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>