Fetch correct dkms version from deban package in post install

kernel/debian/changelog

+anbox-modules-dkms (4) zesty; urgency=medium
+
+  * Fetch dkms version from debian package in post-install step.
+
+ -- Simon Fels <morphis@gravedo.de>  Thu, 23 Feb 2017 19:12:15 +0100
+
 anbox-modules-dkms (3) zesty; urgency=medium
 
   * Use correct package version in our Makefile to avoid failing module
     builds on the target device.
 
- -- Simon Fels <simon.fels@canonical.com>  Tue, 21 Feb 2017 07:36:45 +0100
+ -- Simon Fels <morphis@gravedo.de>  Tue, 21 Feb 2017 07:36:45 +0100
 
 anbox-modules-dkms (1) xenial; urgency=low
 

kernel/debian/prerm

 #!/bin/sh
 
 NAME=anbox-modules-dkms
-VERSION=1
+VERSION=`dpkg-query -W -f='${Version}' $DEB_NAME | awk -F "-" '{print $1}' | cut -d\: -f2`
 
 set -e