LU-10595 mgc: don't proccess cld during stopping

LU-10595 mgc: don't proccess cld during stopping

The patch fixes the log processing during stopping. It was general
protection fault at mgc_process_cfg_log() at lsi access. Lsi pointer
was wrong 38323172756f6663, and all cld->cld_cfg.cfg_sb had invalid
data.

Signed-off-by: Alexander Boyko <c17825@cray.com>
Cray-bug-id: LUS-6199
Change-Id: Ie4f35ba5be707ab8d274cc26fd2c230ffcb0a16e
Reviewed-on: https://review.whamcloud.com/33190
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>