K 10
svn:author
V 3
mjg
K 8
svn:date
V 27
2017-02-09T08:19:30.326684Z
K 7
svn:log
V 223
locks: tidy up unlock fallback paths

Update comments to note these functions are reachable if lockstat is
enabled.

Check if the lock has any bits set before attempting unlock, which saves
an unnecessary atomic operation.

END