A recent change changed this constructor to "init_this_module". This
breaks the build on windows according to AppVeyor. Include the module
name in the constructor name to work around the issue.
Fixes:
922fed065e65 ("vlog: Make the most common module reference more direct.")
Signed-off-by: Russell Bryant <russell@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>