fix(hftest): get response result from correct register

FFA_MSG_SEND_DIRECT_RESP_32 sets the result in arg3, some tests were
looking in arg2 instead, bound to 0 and incidentally having the same
value as SP_SUCCESS.

Change-Id: Ic72d3fe32c0ec4e30242f7b5f031685c1d130396
Signed-off-by: Federico Recanati <federico.recanati@arm.com>
diff --git a/test/vmapi/ffa_secure_partitions/dir_msg.c b/test/vmapi/ffa_secure_partitions/dir_msg.c
index 88f73e2..7610849 100644
--- a/test/vmapi/ffa_secure_partitions/dir_msg.c
+++ b/test/vmapi/ffa_secure_partitions/dir_msg.c
@@ -51,7 +51,7 @@
 				   msg[3]);
 
 	EXPECT_EQ(res.func, FFA_MSG_SEND_DIRECT_RESP_32);
-	EXPECT_EQ(res.arg2, SP_SUCCESS);
+	EXPECT_EQ(sp_resp(res), SP_SUCCESS);
 }
 
 /**
@@ -67,5 +67,5 @@
 	res = sp_req_echo_busy_cmd_send(own_id, receiver_id);
 
 	EXPECT_EQ(res.func, FFA_MSG_SEND_DIRECT_RESP_32);
-	EXPECT_EQ(res.arg2, SP_SUCCESS);
+	EXPECT_EQ(sp_resp(res), SP_SUCCESS);
 }
diff --git a/test/vmapi/ffa_secure_partitions/services/partition_services.c b/test/vmapi/ffa_secure_partitions/services/partition_services.c
index bab6545..e5ebacf 100644
--- a/test/vmapi/ffa_secure_partitions/services/partition_services.c
+++ b/test/vmapi/ffa_secure_partitions/services/partition_services.c
@@ -53,7 +53,7 @@
 		res = sp_req_echo_busy_cmd_send(own_id, own_id + 1);
 
 		EXPECT_EQ(res.func, FFA_MSG_SEND_DIRECT_RESP_32);
-		EXPECT_EQ(res.arg2, SP_SUCCESS);
+		EXPECT_EQ(sp_resp(res), SP_SUCCESS);
 	}
 
 	return sp_success(own_id, test_source);