[SCSI] ps3rom: fix wrong resid calculation bug

sg driver rounds up the length in struct scatterlist to be a multiple
of 512 in some conditions. So LLDs can't use the data length in a sg
list to calculate residual. Instead, the length in struct scsi_cmnd
should be used.

[Geert: the variable buflen already contains scsi_bufflen(cmd)]

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/ps3rom.c

@@ -124,7 +124,7 @@ static int fill_from_dev_buffer(struct scsi_cmnd *cmd, const void *buf)
 		}
 		req_len += sgpnt->length;
 	}
-	scsi_set_resid(cmd, req_len - act_len);
+	scsi_set_resid(cmd, buflen - act_len);
 	return 0;
 }