kiss-owns: fix usage with KISS_ROOT (#86)

Co-authored-by: git-bruh <e817509a-8ee9-4332-b0ad-3a6bdf9ab63f@aleeas.com>
Reviewed-on: https://codeberg.org/kiss-community/kiss/pulls/86

contrib/kiss-owns

@@ -4,7 +4,8 @@
 # Follow symlinks to any paths.
 case $1 in
     /*)
-        cd -P "$KISS_ROOT${1%/*}"
+        cd -P "${KISS_ROOT:-/}${1%/*}"
+        [ "$PWD" = / ] && KISS_ROOT=
     ;;
 
     */*)
@@ -24,7 +25,7 @@ esac
 # Print the full path to the manifest file which contains
 # the match to our search.
 pkg_owns=$(grep -lFx \
-    "$PWD/${1##*/}" \
+    "${PWD#"$KISS_ROOT"}/${1##*/}" \
     "$KISS_ROOT/var/db/kiss/installed/"*/manifest)