[SCSI] random: remove redundant SA_SAMPLE_RANDOM from NinjaSCSI

The scsi layer is already calling add_disk_randomness in scsi_end_request.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>