Ruby

win32.c: suppress a warning

• win32/win32.c (get_attr_vsn): assume GetLastError() never return
  0, to suppress a maybe-uninitialized warning in wrename().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51773 b2dd03c8-39d4-4d8f-98ff-823fe69b080e