After 3d41e4d83895 ("passt-repair: Correct off-by-one error verifying
name"), Coverity Scan isn't convinced anymore about the fact that the
ev->name used in the snprintf() is NULL-terminated.
It comes from a read() call, and read() of course doesn't terminate
it, but we already check that the byte at ev->len - 1 is a NULL
terminator, so this is actually a false positive.
In any case, the logic ensuring that ev->name is NULL-terminated isn't
necessarily obvious, and additionally checking that the last byte in
the buffer we read is a NULL terminator is harmless, so do that
explicitly, even if it's redundant.
Signed-off-by: Stefano Brivio