win32: Change some APIs to use DWORD instead of size_t

win32: Change some APIs to use DWORD instead of size_t

This is what the Win32 APIs use. Since we put static
integers into this (e.g. sizeof()) this doesn't
result in new conversion warnings at the caller sites.

Change-Id: Ia836e3c05a868a7e8419c2bb2f547d968260783c
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1269
Message-Id: <20251013162221.2156-1-gert@greenie.muc.de>
URL: https://sourceforge.net/p/openvpn/mailman/message/59246222/
Signed-off-by: Gert Doering <gert@greenie.muc.de>