Fix a typo in a bytecode_to_tree comment

kernel/modelverse_jit/bytecode_to_tree.py

@@ -500,7 +500,7 @@ class AnalysisState(object):
         # lines of:
         #
         #     _globals, = yield [("RD", [task_root, "globals"])]
-        #     global_var = yield [("RD", [_globals, var_name])]
+        #     global_var, = yield [("RD", [_globals, var_name])]
         #
         #     if global_var is None:
         #         global_var, = yield [("CN", [])]