Merge changes I40a11748,I5e56f17f,Ie3748b6c,I4e1d56a8 into nyc-dev

* changes:
  adb: use asocket's close function when closing.
  adb: switch the socket list mutex to a recursive_mutex.
  adb: clang-format sockets.cpp.
  adb: add implementations of mutex, recursive_mutex.