Hitachi: fix to initialize a lock counter

This patch fixes Hitachi driver to initialize a lock counter, in a
method to re-login to REST-API server,
for fixing the bug which send unnecessary request to unlock storage
resource group.

Closes-Bug: #2033448
Change-Id: I8d0da7bf499bc4ac352949c942c41494a51b3874

cinder/volume/drivers/hitachi/hbsd_rest_api.py

@@ -537,6 +537,7 @@ class RestApiClient():
                                  timeout=self.conf.hitachi_lock_timeout)
         if not err:
             self.set_my_session(self.Session(rsp["sessionId"], rsp["token"]))
+            self.nested_count = 0
             return True
         else:
             return False
@@ -574,6 +575,7 @@ class RestApiClient():
                 retry = self._has_session()
                 if not retry:
                     LOG.debug("Trying to re-login.")
+                    self.nested_count = 0
                     retry = self._login(do_raise=False)
                 if not retry:
                     self.output_log(

releasenotes/notes/hitachi-fix-unlock-f4e044807985e60b.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Hitachi driver `bug #2033448
+    <https://bugs.launchpad.net/cinder/+bug/2033448>`_: Fixed to initialize
+    lock counter for resource group