Only look for this rip's log file in output directory

Signed-off-by: Katharina Dröge <kate@commandmc.de>

whipper/command/cd.py

@@ -378,8 +378,8 @@ Log files will log the path to tracks relative to this directory.
                                         self.program.metadata)
         dirname = os.path.dirname(discName)
         if os.path.exists(dirname):
-            logs = glob.glob(os.path.join(glob.escape(dirname), '*.log'))
-            if logs:
+            log_file = discName + '.log'
+            if os.path.exists(log_file):
                 msg = ("output directory %s is a finished rip" % dirname)
                 logger.debug(msg)
                 raise RuntimeError(msg)