engine: Fix brick validation during create volume

while creating a volume, the bricks will be validated
against the entries in gluster_volume_bricks table.

The above check is already present during add bricks(after volume creation),
now this is included in create volume as well.

Change-Id: Ie5c9afac29c2c982544b636c9d731ac39803cc7c
Bug-Url: https://bugzilla.redhat.com/856109
Signed-off-by: Kanagaraj M <kmayilsa@redhat.com>