This improves readability and simplifies the code.

Cc: Andreas Färber <andreas.faerber@web.de>
Cc: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>