Fix walrus comprehension test expectation

Author: EltonChang1

test-data/unit/check-redefine2.test

@@ -339,7 +339,7 @@ def f() -> None:
     x = 0
     xs = [x := "" for _ in [0]]
     reveal_type(xs) # N: Revealed type is "builtins.list[builtins.str]"
-    reveal_type(x) # N: Revealed type is "builtins.str"
+    reveal_type(x) # N: Revealed type is "builtins.int"
 
     x = 1.0
     reveal_type(x) # N: Revealed type is "builtins.float"