Add va_end() to early return from putil_log_failure

[jcpunk]

Noticed a possible issue with a missing va_end().

[rra]

Thank you! I had noticed this a while back in the version of the file in rra-c-util but hadn't merged the fix, which I did now.

For the record, your fix is correct on systems that allocate memory in the va_start macro, but not in systems in which va_start opens a block, since then there has to be a one-for-one pairing of va_start and va_end. I checked in a slightly different fix that just moves the va_end up above the conditional.