Fix incorrect end epoch comment (#3612)

train.py

@@ -341,8 +341,7 @@ def train(hyp, opt, device, tb_writer=None):
                                                   save_dir.glob('train*.jpg') if x.exists()]})
 
             # end batch ------------------------------------------------------------------------------------------------
-        # end epoch ----------------------------------------------------------------------------------------------------
+        
-
         # Scheduler
         lr = [x['lr'] for x in optimizer.param_groups]  # for tensorboard
         scheduler.step()