replace-tar-coreutils: Purge mktemp before installing coreutils

The mktemp utility is now being shipped by coreutils, so the mktemp
package has to be removed before coreutils gets installed to avoid
file conflicts.

Signed-off-by: Emanuele Aina <emanuele.aina@collabora.com>

scripts/replace-tar-coreutils-for-build.sh

@@ -4,6 +4,7 @@ set -e
 cp /bin/rm /bin/tar /usr/local/bin
 apt-get update
 DPKGPATH=/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+apt-get -y -o Dpkg::Path="$DPKGPATH" --allow-remove-essential purge mktemp
 apt-get -y -o Dpkg::Path="$DPKGPATH" install coreutils tar
 rm /usr/local/bin/rm /usr/local/bin/tar