ctdb: Fix rootfs creation errors

While building an image I was getting an error during rootfs creation
that ctdb was conflicting with base-files as both were creating
'/var/run':

    warning: Removing ctdb-2.5.1-r0@core2_64 due to file /var/run \
      conflicting with base-files-3.0.14-r89@genericx86_64

This is normally a volatile directory so we have no need
to include this in the ctdb package, so revert the actions of the
Makefile by deleting the directory.

Although /run and $localstatedir/run are linked to be consistent we
update the .service file to use the latter. To ensure the 'ctdb'
subdir exists we patch the use of RuntimeDirectory= in to the .service
file. This will compensate for our removal of this directory creation
from the Makefile.

Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>