Commit 663c74150a
(makepkg: merge arch dependent variables after PKGBUILD linting) broke
"makepkg -g" on a PKGBUILD which did not include the current architecture, by
moving the lint_pkgbuild call before GENINTEG was processed.
Fix that by setting IGNOREARCH for the "-g" option.
Signed-off-by: Allan McRae <allan@archlinux.org>