winhttp: Fix return value for relative redirects.

dlls/winhttp/request.c

@@ -2575,6 +2575,7 @@ static DWORD handle_redirect( struct request *request, DWORD status )
         }
         free( request->path );
         request->path = path;
+        ret = ERROR_SUCCESS;
 
         send_callback( &request->hdr, WINHTTP_CALLBACK_STATUS_REDIRECT, location, len_loc + 1 );
     }