Revert "[Enhancement] Change assertion logic inference cfg.model.test…

…_cfg (#3012)"

This reverts commit b0635ff.

mmseg/models/segmentors/encoder_decoder.py

@@ -33,7 +33,7 @@ class EncoderDecoder(BaseSegmentor):
     2. The ``predict`` method is used to predict segmentation results,
     which includes two steps: (1) Run inference function to obtain the list of
     seg_logits (2) Call post-processing function to obtain list of
-    ``SegDataSample`` including ``pred_sem_seg`` and ``seg_logits``.
+    ``SegDataSampel`` including ``pred_sem_seg`` and ``seg_logits``.
 
     .. code:: text
 
@@ -326,9 +326,8 @@ def inference(self, inputs: Tensor, batch_img_metas: List[dict]) -> Tensor:
             Tensor: The segmentation results, seg_logits from model of each
                 input image.
         """
-        assert self.test_cfg.get('mode', 'whole') in ['slide', 'whole'], \
-            f'Only "slide" or "whole" test mode are supported, but got ' \
-            f'{self.test_cfg.mode}'
+
+        assert self.test_cfg.mode in ['slide', 'whole']
         ori_shape = batch_img_metas[0]['ori_shape']
         assert all(_['ori_shape'] == ori_shape for _ in batch_img_metas)
         if self.test_cfg.mode == 'slide':