[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 <[e-mail]>
Signed-off-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/ps3rom.c

···
 		}
 		req_len += sgpnt->length;
 	}
-	scsi_set_resid(cmd, req_len - act_len);
+	scsi_set_resid(cmd, buflen - act_len);
 	return 0;
 }