pypy3 compilation fix for locking callback (#3716)

* pypy3 fix on macos using work from the pypy project

https://bitbucket.org/pypy/pypy/commits/198dc138680f96c391802fa1e77b8b6d2e0134e6?at=py3.5

* change abort error msg and fix wrong type

* oh windows

* remove an unused variable

* rename mutex1_t, use calloc, small style fixes

* calloc correctly

* (call)
1 file changed