staging: unisys: visorbus: Remove useless checks in visorbus_main.c

Removes checks that all visor_device instances have an associated
visorchannel. Due to the design of the s-Par drivers these checks are
unnecessary.

Signed-off-by: David Binder <david.binder@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Reviewed-by: Tim Sell <timothy.sell@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>