staging: unisys: visorchannel_create_guts(): Use visorchannel_read()

There is no benefit to calling visor_memregion_read() at this point.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>