sendmmsg
ret = sendmmsg(b->num, mh, num_msg, sysflags);
ssize_t sendmmsg(int, struct mmsghdr * __restrict, size_t, int);
EXPECT_FAIL_NOT_CAPMODE(sendmmsg(fd_socket, &mm, 1, 0));
EXPECT_NOTCAPABLE(sendmmsg(cap_sock_rw, &mv, 1, 0));
EXPECT_OK(sendmmsg(cap_sock_connect, &mv, 1, 0));