Correct typos in auto3dseg tutorial (#995)

Signed-off-by: dongyang0122 <don.yang.mech@gmail.com>

Corrected typos in auto3dseg tutorial.

### Description
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- [ ] Notebook runs automatically `./runner [-p <regex_pattern>]`

Signed-off-by: dongyang0122 <don.yang.mech@gmail.com>

Author: dongyang0122

auto3dseg/docs/ensemble.md

@@ -23,7 +23,7 @@ data_src_cfg = "./task.yaml"
 ## algorithm generation
 bundle_generator = BundleGen(
     algo_path=work_dir,
-    data_stats_filename=da_output_yaml,
+    data_stats_filename=data_output_yaml,
     data_src_cfg_name=data_src_cfg,
 )