printllval: handle s390x

printllval: handle s390x

This is a 64bit arch w/no personalities, so fix printing.
It can now trace a simple call like readahead:
$ cat test.c
main(){readahead(-1, (unsigned long long)1 << 50, 0);}
$ gcc test.c
$ ./strace -ereadahead ./a.out
readahead(-1, 1125899906842624, 0)      = -1 EBADF (Bad file descriptor)

* util.c (printllval): Handle S390X define.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>