fix: fix bad initialization script error message

Author: Namrata Madan

src/sagemaker/workflow/notebook_job_step.py

@@ -248,7 +248,7 @@ def _validate_inputs(self):
 
         # init script is optional
         if self.initialization_script and not os.path.isfile(self.initialization_script):
-            errors.append(f"The initialization script({self.input_notebook}) is not a valid file.")
+            errors.append(f"The initialization script({self.initialization_script}) is not a valid file.")
 
         if self.additional_dependencies:
             for path in self.additional_dependencies: