Remove bashism from kxsconfig/update_hacks.sh

tdescreensaver/kxsconfig/update_hacks.sh

@@ -11,13 +11,16 @@ fi
 
 # Gets list of screensavers. Exclude 'config'.
 scsvs=""
-pushd "${XSDIR}" >/dev/null
-for i in *; do
+if [ -d "$XSDIR" ]; then
+  LASTD=$PWD
+  cd "${XSDIR}" >/dev/null
+  for i in *; do
     if [ "${i}" != "config" ]; then
       scsvs="${scsvs} ${i}"
     fi
-done
-popd >/dev/null
+  done
+  cd "$LASTD"
+fi
 
 echo $scsvs