message: Fix typo in a message.
diff: @@ -746,7 +746,7 @@ Status MemoryUsageTracker::EndInstruction() {
  Buffer& buffer = buffers_.at(buffer_id);
  buffer.unfinished_user_count--;
  CHECK_GE(buffer.unfinished_user_count, 0)
  - << buffer.ToString() << " has negative unfinished use count.";
  + << buffer.ToString() << " has negative unfinished user count.";
  if (buffer.unfinished_user_count == 0) {
  // Buffer is now dead.
  VLOG(3) << " " << buffer.ToString() << " is now dead.";
  