Fix embeddings for PyTorch 1.8 (#10549)

* Fix embeddings for PyTorch 1.8

* Try with PyTorch 1.8.0

* Fix embeddings init

* Fix copies

* Typo

* More typos

src/transformers/models/bert/modeling_bert.py

@@ -704,15 +704,19 @@ class BertPreTrainedModel(PreTrainedModel):
 
     def _init_weights(self, module):
         """ Initialize the weights """
-        if isinstance(module, (nn.Linear, nn.Embedding)):
+        if isinstance(module, nn.Linear):
             # Slightly different from the TF version which uses truncated_normal for initialization
             # cf https://github.com/pytorch/pytorch/pull/5617
             module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
+            if module.bias is not None:
+                module.bias.data.zero_()
+        elif isinstance(module, nn.Embedding):
+            module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
+            if module.padding_idx is not None:
+                module.weight.data[module.padding_idx].zero_()
         elif isinstance(module, nn.LayerNorm):
             module.bias.data.zero_()
             module.weight.data.fill_(1.0)
-        if isinstance(module, nn.Linear) and module.bias is not None:
-            module.bias.data.zero_()
 
 
 @dataclass