LU-15094 o2iblnd: map_on_demand not needed for frag interop

LU-15094 o2iblnd: map_on_demand not needed for frag interop

The map_on_demand tunable is not used for setting max frags so don't
require that it be set in order to negotiate max frags.

Lustre-change: https://review.whamcloud.com/45215
Lustre-commit: 4e61a4aacdbc2376069d52d0f803a9f05315080f

HPE-bug-id: LUS-10488
Test-Parameters: trivial
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: Ie89f1f035f4b05244feffb848c14582a8c7cf0e6
Reviewed-on: https://review.whamcloud.com/46453
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>