refactor: remove straggling boost::mutex usage #21010

1. 
   fanquake commented at 7:59 am on January 26, 2021: member

   After the merge of #18710, the linter is warning:

   0A new Boost dependency in the form of "boost/thread/mutex.hpp" appears to have been introduced:
   1src/sync.cpp:#include <boost/thread/mutex.hpp>
   2src/test/sync_tests.cpp:#include <boost/thread/mutex.hpp>
   3
   4^---- failure generated from test/lint/lint-includes.sh
   

   #18710 removed boost/thread/mutex.hpp from lint-includes, however in the interim #19337 was merged, which introduced more boost::mutex usage.

   Given we no longer use boost::mutex, just remove the double lock test and remaining includes.

2. refactor: remove straggling boost::mutex usage

   After the merge of #18710, the linter is warning:
   ```bash
   A new Boost dependency in the form of "boost/thread/mutex.hpp" appears to have been introduced:
   src/sync.cpp:#include <boost/thread/mutex.hpp>
   src/test/sync_tests.cpp:#include <boost/thread/mutex.hpp>
   
   ^---- failure generated from test/lint/lint-includes.sh
   ```
   
   the interim #19337 was merged, which introduced more `boost::mutex` usage.
   
   Given we no longer use `boost::mutex`, just remove the double lock test
   and remaining includes.

   f827e151a2
3. fanquake added the label Refactoring on Jan 26, 2021
4. 
   laanwj commented at 8:07 am on January 26, 2021: member

   Code review ACK f827e151a2ce96e14aadb9e7d25045fe0a8afbd2 (let’s merge this once CI passes to fix CI)
5. hebasto approved
6. 
   hebasto commented at 8:07 am on January 26, 2021: member

   ACK f827e151a2ce96e14aadb9e7d25045fe0a8afbd2

   Also see #19337 (review)

7. MarcoFalke merged this on Jan 26, 2021
8. MarcoFalke closed this on Jan 26, 2021

   ---

9. fanquake deleted the branch on Jan 27, 2021
10. DrahtBot locked this on Aug 16, 2022

Contributors
fanquake laanwj hebasto

Labels
Refactoring