LU-11185 mgc: config lock leak

LU-11185 mgc: config lock leak

Regression introduced by "LU-580: update mgc llog process code".
It takes additional cld reference to the lock, but lock cancel forget
during normal shutdown. So this lock holds cld on the list for a long
time. any config modification needs to cancel each lock separately.

Cray-bugid: LUS-6253
Fixes: 5538eee216a1 ("LU-580: update mgc llog process code")

Signed-off-by: Alexey Lyashkov <c17817@cray.com>
Change-Id: Ic83e42666bf788739a2f81ab0c66632daa329290
Reviewed-on: https://review.whamcloud.com/32890
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexandr Boyko <c17825@cray.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>