{Core} Allow exception_handler to mute exception (#15306)

src/azure-cli-core/azure/cli/core/commands/__init__.py

@@ -706,8 +706,7 @@ class AzCliCommandInvoker(CommandInvoker):
             return event_data['result']
         except Exception as ex:  # pylint: disable=broad-except
             if cmd_copy.exception_handler:
-                cmd_copy.exception_handler(ex)
-                return CommandResultItem(None, exit_code=1, error=ex)
+                return cmd_copy.exception_handler(ex)
             six.reraise(*sys.exc_info())
 
     def _run_jobs_serially(self, jobs, ids):