removed self.model refs

pytorch_lightning/models/trainer.py

@@ -27,6 +27,7 @@ def reduce_distributed_output(output, nb_gpus):
             output[k] = reduced
     return output
 
+
 class Trainer(TrainerIO):
 
     def __init__(self,
@@ -427,7 +428,6 @@ class Trainer(TrainerIO):
             loss.backward()
 
         if self.check_grad_nans:
-
             model = self.model.module if self.data_parallel else self.model
             for param in model.parameters():
                 print(param.grad.float().sum())