Refactor codebase to use `trainer.loggers` over `trainer.logger` when needed (#11920)

Summary:
### New commit log messages
- [7e2f9fbad Refactor codebase to use `trainer.loggers` over `trainer.logger` when needed (#11920)](https://github.com/PyTorchLightning/pytorch-lightning/pull/11920)

Reviewed By: edward-io

Differential Revision: D34583686

fbshipit-source-id: 98e557b761555c24ff296fff3ec6881d141fa777

d2go/utils/testing/lightning_train_helper.py

@@ -14,7 +14,7 @@ def get_lt_trainer(output_dir: str, cfg):
         if cfg.TEST.EVAL_PERIOD > 0
         else cfg.SOLVER.MAX_ITER,
         callbacks=[checkpoint_callback],
-        logger=None,
+        logger=False,
     )
 
 

tests/runner/test_runner_lightning_task.py

@@ -37,7 +37,7 @@ class TestLightningTask(unittest.TestCase):
             limit_train_batches=1,
             num_sanity_val_steps=0,
             callbacks=[checkpoint_callback],
-            logger=None,
+            logger=False,
         )
 
     def _compare_state_dict(
@@ -200,7 +200,7 @@ class TestLightningTask(unittest.TestCase):
             limit_train_batches=1,
             num_sanity_val_steps=0,
             callbacks=callbacks,
-            logger=None,
+            logger=False,
         )
         with EventStorage() as storage:
             task.storage = storage