bisect-kit: reformat using yapf 0.27.0

yapf in depot_tools was updated to 0.27.0 recently.

BUG=None
TEST=yapf

Change-Id: I2566fe1f479f8e6c9b0e272215f9502002af2794
diff --git a/bisect_kit/codechange.py b/bisect_kit/codechange.py
index 48bc7ba..6f7b8c1 100644
--- a/bisect_kit/codechange.py
+++ b/bisect_kit/codechange.py
@@ -1007,8 +1007,8 @@
     cache_dir = os.path.join(self.root_dir, _DIFF_CACHE_DIR)
     cache_filename = os.path.join(cache_dir, '%s,%s.json' % (old, new))
     if not os.path.exists(cache_filename):
-      raise errors.InternalError(
-          'cached revlist not found: %s' % cache_filename)
+      raise errors.InternalError('cached revlist not found: %s' %
+                                 cache_filename)
 
     result = []
     with open(cache_filename) as f: