coreutils cleanup

[Tobias Gasser]

running the tests from coreutils, the sources can't be removed as a 
mountpoint within the test is not unmounted.

solution:


MNT=$( mount | grep coreutils | awk '{print 3}' )
for i in $MNT ; do
   umount $i >/dev/null
done


i added this lines after "make install" quite some time ago to both 
chapter 5 and 6. immediate after the make check the mountpoint often 
seems to be still in use, but after install i could always unmount.

i'd propose to add this to the coreutils script.

thanks
tobias