Fix lint issues in research/disk (#741)

Summary:
Pull Request resolved: #741

As title

Reviewed By: EnayatUllah

Differential Revision: D70909809

fbshipit-source-id: e883a1fc0162b07d0e37ca13b45102be532d1607

Author: iden-kalemaj

research/disk_optimizer/optimizers/KFoptimizer_fast_gradient_clipping.py

@@ -30,7 +30,10 @@
 logger = logging.getLogger(__name__)
 logger.disabled = True
 
-class KF_DPOptimizerFastGradientClipping(DPOptimizerFastGradientClipping, KF_DPOptimizer):
+
+class KF_DPOptimizerFastGradientClipping(
+    DPOptimizerFastGradientClipping, KF_DPOptimizer
+):
     def __init__(
         self,
         optimizer: Optimizer,