cciss: 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: Stephen M. Cameron <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/block/cciss.c

···
 			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;