post-receive-email has one place where the variable fast_forward is not
spelled correctly. At the same place the logic was reversed. The
combination of both bugs made the script work correctly for fast-forward
commits but not for non-fast-forward ones. This change fixes this to
be correct in both cases.
Signed-off-by: Robert Schiele <rschiele@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>