Set the scsi_level correctly for disk arrays such
that things like the rotational field get set
properly by sd.c.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Reviewed-by: Wen Xiong<wenxiong@linux.vnet.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>