[dvipdfmx] dvipdfmx: wrong exit status

[Shunsaku Hirata]

> P.S. On another, much more important, front, do the proposed changes to
> fix the weird strncmp problem look ok?

The proposed patch should work. However, as the input data to be
compared is, in general cases, not necessarily a C string although
it is currently null terminated, I will consider adding a size check of
data before the memcmp comparison.

Thanks,
Shunsaku Hirata