magit/magit — pull request #903 by praet (2013-09-18 07:21:02+00:00)
Title: `magit-wash-log': call `derived-mode-p' only once

Doing the same thing twice for no additional benefit is always a pain,
so `let'-bind the return value of `derived-mode-p' around the body form.

Signed-off-by: Pieter Praet