The check-tcg plugins build was failing because some special case
tests that needed -cpu max failed because the plugin variant hadn't
carried across the QEMU_OPTS tweak.
Guests which globally set QEMU_OPTS=-cpu FOO where unaffected.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20200615141922.18829-3-alex.bennee@linaro.org>