fdrelease
(void) fdrelease(p, epp->ep_fd);
(void) fdrelease(p, fd);
fdrelease(p, i);
error = fdrelease(p, fd);
(void) fdrelease(p, pack.ep_fd);
fdrelease(p, fds[0]);
fdrelease(p, fds[1]);
int fdrelease(struct proc *p, int);