tests/restart_syscall.c: use libtests
tests/restart_syscall.c: use libtests

* tests/restart_syscall.c (main): Use assert, perror_msg_and_fail,
and perror_msg_and_skip.

Saruta/strace,cuviper/strace,Saruta/strace,Saruta/strace,cuviper/strace,cuviper/strace,Saruta/strace,cuviper/strace,cuviper/strace,Saruta/strace