fget_cap_noref
error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp);
error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL);
error = fget_cap_noref(fdp, fd, cap_rights_init_one(&rights, CAP_TTYHOOK),
int fget_cap_noref(struct filedesc *fdp, int fd,