[Tools] testbot: Document CompareJobPriority(), particularly the Priority field.

Its naming is quite unfortunate since higher values mean a lower
priority.

Signed-off-by: Francois Gouget <[email protected]>
---
 testbot/lib/WineTestBot/Jobs.pm | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/testbot/lib/WineTestBot/Jobs.pm b/testbot/lib/WineTestBot/Jobs.pm
index f6c19595..f42b88d7 100644
--- a/testbot/lib/WineTestBot/Jobs.pm
+++ b/testbot/lib/WineTestBot/Jobs.pm
@@ -400,6 +400,8 @@ sub CreateJobs(;$)
 
 sub CompareJobPriority
 {
+  # Process Jobs with a higher Priority value last (it's a niceness in fact),
+  # and older Jobs first.
   return $a->Priority <=> $b->Priority || $a->Id <=> $b->Id;
 }
 
-- 
2.14.2