The condition  '!A || (A && B)' is equivalent to '!A || B'

Buglink: https://bugs.launchpad.net/qemu/+bug/1464611


Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>