Fix counting of images at build time

Closes: #1063858

debian/changelog

@@ -9,6 +9,7 @@ debian-cd (3.2.2) UNRELEASED; urgency=medium
   * Tweak sizes slightly for BD media.
   * Look for firmware in /usr/lib/firmware as well as /lib/firmware.
     Closes: #1059858
+  * Fix counting of images at build time. Closes: #1063858
 
   [ Guido Berhoerster ]
   * Update DebianEdu installer banner and syslinux splash image

tools/make_image

@@ -19,13 +19,11 @@ NUM_ARCHES=`echo $ARCHES | wc -w`
 
 if [ "$CD"x = ""x ] ; then
     echo "Generating the $ARCHES iso/jigdo images ..."
-    FILES=$DIR/*.volid
 else
     echo "Generating $ARCHES iso/jigdo image number $CD ..."
-    FILES=$DIR/$CD.volid
 fi
 
-NUM_CDS=`ls -1 $FILES | wc -l`
+NUM_CDS=$(ls -1 $DIR/*.volid | wc -l)
 
 last_minute_update () {
     echo "  Last-minute updates:"