kunit: Fix wrong parameter to kunit_deactivate_static_stub()

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: e047c5eaa763 ("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>