[PATCH 1 of 5 STABLE V2] dockerdeb: elimate 'cd' in export command

[Sean Farley]

# HG changeset patch
# User Sean Farley <sean at farley.io>
# Date 1460914600 25200
#      Sun Apr 17 10:36:40 2016 -0700
# Branch stable
# Node ID b7fb0360f172f06477a07bf510aca176109c0cba
# Parent  e442b628bfe6485d57ab4f10f941b89e96f04b05
# EXP-Topic ppa
dockerdeb: elimate 'cd' in export command

This had the unfortunate side effect of causing the environment to have a
newline due to the fact that some 'cd' outputs the result of the directory
change.

diff --git a/contrib/dockerdeb b/contrib/dockerdeb
--- a/contrib/dockerdeb
+++ b/contrib/dockerdeb
@@ -2,11 +2,11 @@
 
 . $(dirname $0)/dockerlib.sh
 . $(dirname $0)/packagelib.sh
 
 BUILDDIR=$(dirname $0)
-export ROOTDIR=$(cd $BUILDDIR/..; pwd)
+export ROOTDIR=$(dirname $BUILDDIR)
 
 checkdocker
 
 DISTID="$1"
 CODENAME="$2"