Fix linting errors

Change-Id: I16d01e15438e3d61033863b4c03087d1a0b7a008

charms_ceph/utils.py

@@ -2518,7 +2518,7 @@ class WatchDog(object):
         :type timeout: int
         """
         start_time = time.time()
-        while(not wait_f()):
+        while not wait_f():
             now = time.time()
             if now > start_time + timeout:
                 raise WatchDog.WatchDogTimeoutException()
@@ -3418,7 +3418,7 @@ def apply_osd_settings(settings):
     set_cmd = base_cmd + ' set {key} {value}'
 
     def _get_cli_key(key):
-        return(key.replace(' ', '_'))
+        return key.replace(' ', '_')
     # Retrieve the current values to check keys are correct and to make this a
     # noop if setting are already applied.
     for osd_id in get_local_osd_ids():

unit_tests/test_utils.py

@@ -2058,7 +2058,7 @@ class CephUseBluestoreTestCase(unittest.TestCase):
                                                     _cmp_pkgrevno):
         _cmp_pkgrevno.return_value = 1
         _config.return_value = True
-        assert(utils.use_bluestore())
+        assert (utils.use_bluestore())
 
     @patch.object(utils, 'cmp_pkgrevno')
     @patch.object(utils, 'config')