[SCSI] hpsa: fix flush cache transfer length

We weren't filling in the transfer length of the
flush cache command (it transfers 4 bytes of zeroes).
Firmware didn't seem to be bothered by this, but it
should be fixed.
Signed-off-by: NStephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: NJames Bottomley <JBottomley@Parallels.com>

drivers/scsi/hpsa.c

@@ -2876,6 +2876,8 @@ static void fill_cmd(struct CommandList *c, u8 cmd, struct ctlr_info *h,
 			c->Request.Timeout = 0;
 			c->Request.CDB[0] = BMIC_WRITE;
 			c->Request.CDB[6] = BMIC_CACHE_FLUSH;
+			c->Request.CDB[7] = (size >> 8) & 0xFF;
+			c->Request.CDB[8] = size & 0xFF;
 			break;
 		case TEST_UNIT_READY:
 			c->Request.CDBLen = 6;