staging: unisys: Fix double sysfs create for module version

When we combined visorchipset and visorbus into one driver we negelected
to strip out some of the MODULE_ stuff from one of the files.  When
building the drivers in, it causes a WARN that we try to create
/proc/modules/visorbus/version when it is already created.

visorchipset.c is the driver entry point, remove the cruft from
visorbus_main.c.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>