scsi: target: spc: Fix RSOC parameter data header size

[ Upstream commit b50532318793d28a7628c1ffc129a2226e83e495 ]

The SPC document states that "The COMMAND DATA LENGTH field indicates the
length in bytes of the command descriptor list".

The length should be subtracted by 4 to represent the length of the
description list, not 3.

Signed-off-by: Chaohai Chen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Dmitry Bogdanov <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
(cherry picked from commit 93a562eedcd5da087e30d7e35374fe2bad38f88e)
Signed-off-by: Jack Vogel <[email protected]>

Author: Chaohai Chen

drivers/target/target_core_spc.c

@@ -2243,7 +2243,7 @@ spc_emulate_report_supp_op_codes(struct se_cmd *cmd)
 			response_length += spc_rsoc_encode_command_descriptor(
 					&buf[response_length], rctd, descr);
 		}
-		put_unaligned_be32(response_length - 3, buf);
+		put_unaligned_be32(response_length - 4, buf);
 	} else {
 		response_length = spc_rsoc_encode_one_command_descriptor(
 				&buf[response_length], rctd, descr,