precise base-files /var/run migrate_dir fails on pkg configure

Using precise, multistrap and live-build to build Linaro images, we have noted the following bug in base-files. In debian/postinst.in on line 26 we have

     26 migrate_directory() {
     27 if [ ! -L $1 ]; then
     28 rmdir $1
     29 ln -s $2 $1
     30 fi
     31 }

Note that due to multistrap later on in this same file line 55, will fail cause when the dpkg --configure -a step happens /var/run already exists and is not certain to be empty causing rmdir to fail..

     54 install_directory run/lock 1777 root
     55 migrate_directory /var/run /run

The directory as part of the configure step can be safely blow away. Thus the fix recommended is :

     26 migrate_directory() {
     27 if [ ! -L $1 ]; then
     28 rm -rf $1
     29 ln -s $2 $1
     30 fi
     31 }

Please apply.