'git log --decorate=' understands the 'full', 'short' and 'no' options.
From these the completion script only offered 'short' and it offered
'long' instead of 'full'.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>