some filter's info is missing in source/devref/filter_scheduler.rst

[jichenjc]

in doc/source/devref/filter_scheduler.rst, it describe the filters as reference

DiskFilter
NumInstancesFilter
PciPassthroughFilter

are missing and should be added

(BTW, don't know whether it's proper to open a doc defect through bug here, let me know a better way if you have ,thanks)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/71556

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/71556
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=35637ff21817e20899a88d46f26aa369e6def2df
Submitter: Jenkins
Branch: master

commit 35637ff21817e20899a88d46f26aa369e6def2df
Author: jichenjc <email address hidden>
Date: Sun Jan 26 23:14:59 2014 +0800

    Add doc update for 4 filters which is missing in filter_scheduler.rst

    DiskFilter
    NumInstancesFilter
    IoOpsFilter
    PciPassthroughFilter
    are missing in doc/source/devref/filter_scheduler.rst, add them.

    DocImpact

    Change-Id: I50868598c9769783e1677c9ec50abf031896af82
    Closes-Bug: #1276575