staging: ccree: remove useless NULL test of field

Remove kbuild test robot reported NULL check for a struct field address.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>