Update torchir_passes.py remove_getattr_nodes() description

Author: tritolol

coremltools/converters/mil/frontend/torch/torchir_passes.py

@@ -231,7 +231,8 @@ def forward(self, x):
 
 def remove_getattr_nodes(graph: InternalTorchIRGraph) -> None:
     """
-    Remove the getattr nodes in the graph that are not output nodes
+    Remove the getattr nodes in the graph
+    If they are output nodes, convert them to constant nodes
     """
 
     new_nodes = []