[hotfix] Correct several erroneous code comments (#4794)

colossalai/shardformer/policies/base_policy.py

@@ -50,7 +50,7 @@ class ModulePolicyDescription:
                         new_weight = shard_rowwise(weight, process_group)
                         module.weight = torch.nn.Parameter(new_weight)
                     ```
-        sub_module_replacement (List[SubModuleReplacementDescription]): each element in the list is a ParamReplacementDescription
+        sub_module_replacement (List[SubModuleReplacementDescription]): each element in the list is a SubModuleReplacementDescription
                     object which specifies the module to be replaced and the target module used to replacement.
         method_replace (Dict[str, Callable]): key is the method name, value is the method for replacement
     """

colossalai/zero/low_level/bookkeeping/bucket_store.py

@@ -92,7 +92,7 @@ class BucketStore(BaseStore):
 
     def get_flatten_grad(self) -> Tensor:
         """Return the flattened gradients slices in the bucket, the data orginization of the flattened tensor:
-        [grad0_rank0, grad1_rank0, ..., grad_1_rank0, grad1_rank1, ....]
+        [grad0_rank0, grad1_rank0, ..., grad_0_rank1, grad1_rank1, ....]
 
         Returns:
             Tensor: the flattened gradients slices in the bucket