staging: unisys: visorhba: replace functionlike macro with function

The `set_no_disk_inquiry_request` function now uses the correct min
macro. Also I removed an unnecessary conditional.

Get rid of u8 casts, u32 len, and u32 lun (which is actually defined
as a u64 in the scsidev->lun field from whence it originated).

Signed-off-by: Alexander Curtin <alexander.curtin@unisys.com>
Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: Erik Arfvidson <erik.arfvidson@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>