LU-15284 llite: access lli_lsm_md with lock in all places

LU-15284 llite: access lli_lsm_md with lock in all places

lli_lsm_md should be accessed with lock in all places. Among all the
changes, ll_rease_page() is inside lock already, except statahead
code.

Test-Parameters: mdscount=2 mdtcount=4 testlist=racer,racer,racer
Signed-off-by: Lai Siyao <lai.siyao@whamcloud.com>
Change-Id: I1e09402812ce51ce7ab80d9529d488cb5b2879ee
Reviewed-on: https://review.whamcloud.com/46355
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>