rpc01: moved common functions to a lib

"Decipher"-functions xdr_receive_data and xdr_send_data are used
by both rpc_server and rpc1, so moved them to a separate library.

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
rpc01: fix compile-time warnings

And also removed host_address logic from rpc_server (since it is not
used there anyway).

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>