only print GraphModule during fx.Interpreter errors if valid (#148090)

Came up in https://www.internalfb.com/diff/D69057074?dst_version_fbid=970771615000938&transaction_fbid=1723357345264461 - we need to make sure the GraphModule is valid before calling `print_readable` on it

Pull Request resolved: https://github.com/pytorch/pytorch/pull/148090
Approved by: https://github.com/jamesjwu, https://github.com/zou3519
ghstack dependencies: #147749

torch/fx/interpreter.py

@@ -173,7 +173,11 @@ class Interpreter:
                 if self.extra_traceback:
                     msg = f"While executing {node.format_node()}"
                     msg = f"{e.args[0]}\n\n{msg}" if e.args else str(msg)
-                    if isinstance(self.module, GraphModule):
+                    if (
+                        isinstance(self.module, GraphModule)
+                        and self.module.graph is not None
+                        and isinstance(self.module.graph, torch.fx.Graph)
+                    ):
                         msg += f"\nGraphModule: {self.module.print_readable(print_output=False, include_stride=True)}\n"
                     msg += f"\nOriginal traceback:\n{node.stack_trace}"
                     e.args = (msg,) + e.args[1:]