ytdl_hook.lua: make exec return a single value

This refactors exec to only return the result of the subprocess command,
and makes the rest of run_ytdl_hook use the fields of this result,
because specifying all those return values multiple times is unwieldy
now that exec is called several times, and this is easier to read
anyway.

I removed the line
err = string.format("%s returned '%d'", err, es)
altogether instead of updating the es variable, because there was no
chance of it being executed since it would only happen when
result.killed_by_us is true, but run_ytdl_hook returns early when it is.

0 files changed, 0 insertions, 0 deletions