With the symlinks utilitysymlinks utility by Mark Lord (offered by many distributions; if yours doesn't have it, build it from sourcesource):
chroot /home/user/system symlinks -cr .
Alternatively, on systems that have a readlink command and a -lname predicate to find (warning: untested code):
cd /home/user/system &&
find . -lname '/*' -exec ksh -c '
for link; do
target=$(readlink "$link")
link=${link#./}
root=${link//+([!\/])/..}; root=${root#/}; root=${root%..}
rm "$link"
ln -s "$root${target#/}" "$link"
done
' _ {} +