close fp after unlock

paddlehub/common/lock.py

@@ -31,6 +31,7 @@ class Lock(object):
         if cmd == self.lock.LOCK_UN:
             Lock._owner = None
             self.lock.flock(fp, cmd)
+            fp.close()
         elif cmd == self.lock.LOCK_EX:
             if Lock._owner is None:
                 Lock._owner = os.getpid()