dm: replace simple_strtoul

Replace obsolete simple_strtoul() with kstrtou8/kstrtouint.

Signed-off-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --cc drivers/md/dm-crypt.c
Simple merge

diff --cc drivers/md/dm-exception-store.c
Simple merge

diff --cc drivers/md/dm-stripe.c
Simple merge