Staging: unisys: Remove unused macros from visorchannel/visorchannel.h

VISORCHANNEL_CHANGE_SERVER_STATE and VISORCHANNEL_CHANGE_CLIENT_STATE
are never used in any of the source so they have been removed.

VISORCHANNEL_CHANGE_CLIENT_STATE would have caused a broken kernel build
after commit  a8d7f21d, but since it was never used the kernel continued
to build.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ken Cox <jkc@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>