kunit: Fix wrong parameter to kunit_deactivate_static_stub()

kunit_deactivate_static_stub() accepts real_fn_addr instead of
replacement_addr.  In the case, it always passes NULL to
kunit_deactivate_static_stub().

Fix it.

Link: https://lore.kernel.org/r/20250520082050.2254875-1-tzungbi@kernel.org
Fixes: e047c5e ("kunit: Expose 'static stub' API to redirect functions")
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Author: Tzung-Bi Shih

lib/kunit/static_stub.c

@@ -96,7 +96,7 @@ void __kunit_activate_static_stub(struct kunit *test,
 
 	/* If the replacement address is NULL, deactivate the stub. */
 	if (!replacement_addr) {
-		kunit_deactivate_static_stub(test, replacement_addr);
+		kunit_deactivate_static_stub(test, real_fn_addr);
 		return;
 	}