live-build/ubuntu-cpc/hooks/030-root-tarball.binary: correct a missing

unmount of /var/{lib,cache}/apt on cleanup, detected via autopkgtests.

debian/changelog

@@ -4,6 +4,8 @@ livecd-rootfs (2.408.16) xenial; urgency=medium
     after mounting a blank /var/lib/apt, so that further operations work
     as expected; otherwise, 'apt-get purge ^grub-.*' fails on s390x because
     no such packages are known to apt.
+  * live-build/ubuntu-cpc/hooks/030-root-tarball.binary: correct a missing
+    unmount of /var/{lib,cache}/apt on cleanup, detected via autopkgtests.
 
  -- Steve Langasek <steve.langasek@ubuntu.com>  Tue, 12 Sep 2017 13:25:58 -0700
 

live-build/ubuntu-cpc/hooks/030-root-tarball.binary

@@ -29,3 +29,5 @@ umount "binary/boot/filesystem.dir/proc"
 umount "binary/boot/filesystem.dir/sys"
 umount -R "binary/boot/filesystem.dir/dev"
 umount "binary/boot/filesystem.dir/tmp"
+umount "binary/boot/filesystem.dir/var/lib/apt"
+umount "binary/boot/filesystem.dir/var/cache/apt"