debian-package.bbclass: do_patch_quilt: simplify series existence check
debian-package.bbclass: do_patch_quilt: simplify series existence check

Signed-off-by: Kazuhiro Hayashi <d6ab13038406a238a56011921c4eda80a48396fd@toshiba.co.jp>

meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian