Fix remaining small issues with the lock sampling.

Fix remaining small issues with the lock sampling.

* Eliminate the now unused lockprofsample flag.  The sample percentage
  has been a function of the wait time an threshold since the previous
  change.

* Eliminate some trailing whitespace that creeped into the previous
  change.

* Eliminate the trailing newline from the event buffer.  Because the
  buffer pointer was not incremented this character was not seen in
  the event log anyway.

* Document the lockProfThreshold global.

Change-Id: Ia1c1fcf862d76f5631601e05e7941e5171fab097