Replace deprecated tenacity.Retrying.call

... by the __call__ method following the deprecation in the tenacity
library[1].

[1] d66af82a70

Change-Id: I48a5572052cd2cf1dd984f0e4be5703f1e6bc558

cinder/utils.py

@@ -613,7 +613,7 @@ def retry(retry_param: Optional[Type[Exception]],
                 reraise=True,
                 retry=retry(retry_param),
                 wait=wait)
-            return r.call(f, *args, **kwargs)
+            return r(f, *args, **kwargs)
 
         return _wrapper