rARC5407e5e5c67e

Fix PhutilLibraryMapBuilder to call the right function in log()

Summary:
`arc liberate` has been broken for a while because the `log` function attempts to call `fwrite` (whose third argument is an integer length) instead of `fprintf`. I think maybe PHP 5 was more lenient about this? Anyway, this bug makes other development somewhat tricky.

The arcanist source in general seems to be split between `fwrite(STDERR, $message."\n")` and `fprintf(STDERR, "%\n", $message)`; I decided to go with the latter.

This…