lvm: Do not use udev to set permissions on vdsm images

udev has changed the rules recently, so setting USER, GROUP, or MODE
will change also the selinux label behind your back. This issue caused
vms to pause after extend, rendering thin provisioning disk useless.

We had a temporary fix, applying a static selinux label on vdsm images,
but this breaks libvirt security. This patch avoids this issue by not
using udev to set any permissions, thus preserving the secure selinux
labels set by libvirt.

This patch replaces the following commits with a simpler and hopefully
longer lasting fix which does not need any platform specific code.

d8d6c17 gitignore: Ingore vdsm-lvm.rule.tpl
00fbc83 lvm: Modify lv selinux label only if not labablled as libvirt image
b2268e4 spec: Enable lvm selinux fix for Fedora
75fc495 lvm: Set libvirt image selinux label on block devices backing vdsm images

Change-Id: I57d9987bf0be19e6e233baaeea10877918eb849b
Bug-Url: https://bugzilla.redhat.com/1149883
Relates-To: https://bugzilla.redhat.com/1147910
Signed-off-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/33875
Reviewed-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/33931
Reviewed-by: Sandro Bonazzola <sbonazzo@redhat.com>
Reviewed-by: Yaniv Bronhaim <ybronhei@redhat.com>