score: fix __get_user/get_user

[ Upstream commit c2f18fa4cbb3ad92e033a24efa27583978ce9600 ]

* should zero on any failure
* __get_user() should use __copy_from_user(), not copy_from_user()

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>