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

win32/win32.c

@@ -4981,9 +4981,12 @@ get_attr_vsn(const WCHAR *path, DWORD *atts, DWORD *vsn)
     DWORD e = 0;
     HANDLE h = open_special(path, 0, FILE_FLAG_OPEN_REPARSE_POINT);
 
-    if (h == INVALID_HANDLE_VALUE) return GetLastError();
+    if (h == INVALID_HANDLE_VALUE) {
+	ASSUME(e = GetLastError());
+	return e;
+    }
     if (!GetFileInformationByHandle(h, &st)) {
-	e = GetLastError();
+	ASSUME(e = GetLastError());
     }
     else {
 	*atts = st.dwFileAttributes;