Check for ERROR_ALREADY_EXISTS for the second CreateDirectoryW call. (#178)
Check for ERROR_ALREADY_EXISTS for the second CreateDirectoryW call. (#178)

* Check for ERROR_ALREADY_EXISTS for the second CreateDirectoryW call.

Handle the case where multiple threads are trying to create the same directory and the second call to CreateDirectoryW can return ERROR_ALREADY_EXISTS.

* Update filesystem.h

* Update filesystem.h

Co-authored-by: Chris Guzak <5ed7aff6478a548ead81615511e671b06eaaa68c@msn.com>
microsoft/wil,microsoft/wil