Rename a status enum member for Mutex::TryLock.

I changed it to kLockFailed, because kUnlocked seemed not to be a
particularly descriptive name.

Change-Id: Ifdb2ecbf0837cc4b6c40036eedd35d609ada747f
4 files changed
tree: 4dae3ddacf5dd4ad3174d631fa070f243c77299a
  1. aos/
  2. doc/
  3. frc971/
  4. output/
  5. vision/
  6. .clang-format
  7. .gitignore
  8. README.txt