Update to latest upstream git HEAD and add patch to fix fortify warning
    
    The upstream git tree has been idle since late June last year. Pull down
    the latest HEAD (ce1a6720f69e) to update sparse to the latest. Also add
    a proposed upstream patch to fix a FORTIFY_SOURCE warning that causes
    the build to break now (bz2171731).
    
    Signed-off-by: Jeff Layton <jlayton@kernel.org>