IB/isert: fix T10-pi check mask setting

A copy/paste bug (probably) caused setting of an app_tag check mask
in case where a ref_tag check was needed.

Fixes: 38a2d0d429f1 ("IB/isert: convert to the generic RDMA READ/WRITE API")
Fixes: 9e961ae73c2c ("IB/isert: Support T10-PI protected transactions")
Cc: stable@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/ulp/isert/ib_isert.c

@@ -2116,7 +2116,7 @@ isert_set_sig_attrs(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs)
 
 	sig_attrs->check_mask =
 	       (se_cmd->prot_checks & TARGET_DIF_CHECK_GUARD  ? 0xc0 : 0) |
-	       (se_cmd->prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x30 : 0) |
+	       (se_cmd->prot_checks & TARGET_DIF_CHECK_APPTAG ? 0x30 : 0) |
 	       (se_cmd->prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x0f : 0);
 	return 0;
 }