We should only try to evaluate the cdb if this is an ATAPI
device, for any other device the 'cdb' field and the cdb_len
has no meaning.

Fixes: cbba5b0eReported-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NTejun Heo <tj@kernel.org>
Tested-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>