Fix iterator element type extraction for yield from

Author: dhanusharer

mypy/checkexpr.py

@@ -1,6 +1,6 @@
 """Expression type checker. This file is conceptually part of TypeChecker."""
 from __future__ import annotations
-from mypy.types import Instance
+
 from mypy.types import Instance, get_proper_type
 
 import enum
@@ -6281,7 +6281,7 @@ def visit_yield_from_expr(self, e: YieldFromExpr, allow_none_return: bool = Fals
         if isinstance(iter_type_proper, Instance) and iter_type_proper.args:
            actual_item_type = iter_type_proper.args[0]
         else:
-           actual_item_type = self.chk.get_generator_yield_type(iter_type, False)
+           actual_item_type = self.chk.get_generator_yield_type(iter_type_proper, False)
 
         self.chk.check_subtype(
             actual_item_type,