git-quiltimport.sh fix --patches handling

git-quiltimport.sh fix --patches handling

When converting git-quiltimport.sh to the new git-rev-part --parseopt
system, the handling of --patches was broken.  We inadvertantly always
attempt to use '--patches' as the value.

This was introduced in the following commit:

    commit e01fbf1a8f185bf6722e828286862a4122269ef7
    Author: Pierre Habouzit <madcoder@debian.org>
    Date:   Sun Nov 4 11:31:01 2007 +0100

        Migrate git-quiltimport.sh to use git-rev-parse --parseopt

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>