lsm: remove LSM_COUNT and LSM_CONFIG_COUNT

Because these are equals to MAX_LSM_COUNT. Also, we can avoid dynamic
memory allocation for ordered_lsms because MAX_LSM_COUNT is a constant.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Paul Moore <paul@paul-moore.com>