s390/uaccess: add missing EX_TABLE entries to __clear_user()

[ Upstream commit 4e1b5a86 ]

For some exception types the instruction address points behind the
instruction that caused the exception. Take that into account and add
the missing exception table entries.

Cc: <stable@vger.kernel.org>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>