Log Message:
terraform,terraform-provider-*: Remove CHECK_RELRO_SKIP

RELRO_SUPPORTED=no is set in lang/go/go-vars.mk which should remove the
need to use CHECK_RELRO_SKIP in go packages. This was not working
previously because check-relro.mk was using "PKGSRC_USE_RELRO" instead
of "_PKGSRC_USE_RELRO".

ok'd jperkin