sockets: remove use of QemuOpts from socket_dgram

sockets: remove use of QemuOpts from socket_dgram

The socket_dgram method accepts a QAPI SocketAddress object
which it then turns into QemuOpts before calling the
inet_dgram_opts helper method. By converting the latter to
use QAPI SocketAddress directly, the QemuOpts conversion
step can be eliminated.

This removes the very last use of QemuOpts from the
sockets code, so the socket_optslist[] array is also
removed.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1452518225-11751-5-git-send-email-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>