At least under some mingw compilers slirp networking fails without declaring
these fields packed.
From: Juha Riihimäki <juha.riihimaki@nokia.com>
Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Signed-off-by: Riku Voipio <riku.voipio@nokia.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>