LU-13756 quota: up_read leak in qmt_pool_lookup

LU-13756 quota: up_read leak in qmt_pool_lookup

qmt_pool_lock is not released if qti_pools_add fails in
qmt_pool_lookup.

Change-Id: Ic2adb44468d51af7aefcbb91279260ae6f85d67a
Signed-off-by: Sergey Cheremencev <sergey.cheremencev@hpe.com>
Reviewed-on: https://review.whamcloud.com/45106
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Vladimir Saveliev <vlaidimir.saveliev@hpe.com>
Reviewed-by: Andrew Perepechko <andrew.perepechko@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>