whatchanged: remove not-even-shorter clause

The closest equivalent is `git log --raw --no-merges`.

Also change to “defaults” (implicit plural).

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: LemmingAvalanche

Documentation/git-whatchanged.adoc

@@ -15,7 +15,7 @@ WARNING
 -------
 `git whatchanged` has been deprecated and is scheduled for removal in
 a future version of Git, as it is merely `git log` with different
-default; `whatchanged` is not even shorter to type than `log --raw`.
+defaults.
 
 DESCRIPTION
 -----------