The script tests for the existance of /dev/root with test -e which fails if
/dev/root is a dangling symlink making the call to ln fail.

Signed-off-by: Justus Winter <4winter@informatik.uni-hamburg.de>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@26483 3c298f89-4303-0410-b956-a3cf2f4a3e73