LU-18086 sec: fix ppp_max_pages

LU-18086 sec: fix ppp_max_pages

Set ppp_max_pages as a number of pool's
elements instead of pages number.

Signed-off-by: Sergey Cheremencev <scherementsev@ddn.com>
Signed-off-by: Artem Blagodarenko <ablagodarenko@ddn.com>
Change-Id: Ic7ce0b7d6416fb7ace8b0b9ed33baeeffa95d13b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55963
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Patrick Farrell <patrick.farrell@oracle.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>