Since delete_this is an ordinary function, it
should not be passed to cb; otherwise it produces
errors when blame windows are closed. Unfortunately,
it is not noticeable when blame is shown in the
master window, so I missed this bug.
Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>