vm/qvm-dom0-update: don't check for template updates here

Also use exit code 100 to notify updates existence (the same way as yum
check-update does).

common/qubes_download_dom0_updates.sh

@@ -52,20 +52,16 @@ else
     PKGS_FROM_CMDLINE=1
 fi
 
-if [ "$CHECK_ONLY" = "1" ]; then
-    # check also for template updates
-    echo "Checking for template updates..." >&2
-    TEMPLATEPKGLIST=`yum check-update -q | cut -f 1 -d ' '`
-    echo "template:$TEMPLATEPKGLIST"
-    echo "dom0:$PKGLIST"
-    exit
-fi
-
 if [ -z "$PKGLIST" ]; then
     # No new updates
     exit 0
 fi
 
+if [ "$CHECK_ONLY" = "1" ]; then
+    echo "Available updates: $PKGLIST"
+    exit 100
+fi
+
 if [ "$DOIT" != "1" -a "$PKGS_FROM_CMDLINE" != "1" ]; then
     zenity --question --title="Qubes Dom0 updates" \
       --text="There are updates for dom0 available, do you want to download them now?" || exit 0