When clicking on the line that connects two commit nodes, gitk
would bring up an error dialog saying "can't read "cflist_top":
no such variable".
This fixes a regression that was introduced with
b967135 ("gitk:
Synchronize highlighting in file view when scrolling diff").
Signed-off-by: Stefan Haller <stefan@haller-berlin.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>