staging: cxd2099: Change kzalloc parameter

Changed the structure tag 'struct cxd' with the variable '*ci' to fix the
following checkpath.pl issue: CHECK: Prefer kzalloc(sizeof(*ci)...) over
kzalloc(sizeof(struct cxd)).

Signed-off-by: Tamara Diaconita <diaconita.tamara@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>