tools: hv: daemon should check type of received Netlink msg

HyperV KVP daemon should check nlmsg_type in received netlink message
header. If message type is NLMSG_DONE daemon can proceed with processing
otherwise it should wait for next message.

Signed-off-by: Tomas Hozza <thozza@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>