remove-old-kernels: Do not try to output removal list if it's empty

Fixes: 573337d ("remove-old-kernels: Change confirmation logic")
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>

remove-old-kernels

@@ -175,16 +175,16 @@ printf "%s" "$keep_kernels"
 [ -n "$other_flavours" ] && echo "Specify -A to remove all kernels of other flavours than $kernel_flavour."
 echo
 
-howmuch=$(echo "$remove_kernels" | grep -c .)
-[ "$howmuch" -eq 1 ] && phrase="this kernel" || phrase="these $BRIGHT$howmuch$NORM kernels"
-echo "Removing $phrase:"
-echo "$remove_kernels"
-
 if [ -z "$apt_args_list" ] ; then
 	echo "Nothing to remove."
 	exit 0
 fi
 
+howmuch=$(echo "$remove_kernels" | grep -c .)
+[ "$howmuch" -eq 1 ] && phrase="this kernel" || phrase="these $BRIGHT$howmuch$NORM kernels"
+echo "Removing $phrase:"
+echo "$remove_kernels"
+
 if [ "$UID" != "0" ]; then
 	echo >&2 "${RED}Warning: This program requires root privileges.$NORM"
 fi