Remove unused logging import and LOG global var

In some modules the global LOG is not used any more. And the import
of logging is not used. This patch removes the unused logging import
and LOG vars.

Change-Id: I794ee719d76f04e70154cf67f726152fbb1ba15a

watcher/decision_engine/strategy/loading/default.py

@@ -19,12 +19,9 @@
 
 from __future__ import unicode_literals
 
-from oslo_log import log
 
 from watcher.common.loader import default
 
-LOG = log.getLogger(__name__)
-
 
 class DefaultStrategyLoader(default.DefaultLoader):
     def __init__(self):

watcher/decision_engine/strategy/strategies/base.py

@@ -37,16 +37,12 @@ which are dynamically loaded by Watcher at launch time.
 """
 
 import abc
-
-from oslo_log import log
 import six
 
 from watcher.common import clients
 from watcher.decision_engine.solution import default
 from watcher.decision_engine.strategy.common import level
 
-LOG = log.getLogger(__name__)
-
 
 @six.add_metaclass(abc.ABCMeta)
 class BaseStrategy(object):