Use test_bit for RPC_PRIVATE in homa_rpc_get_info

* RPC_PRIVATE is a bit number (2), set with set_bit, but
  homa_rpc_get_info tested it as a mask, which checks bit 1
  (APP_NEEDS_LOCK). HOMAIOCINFO therefore never reported
  HOMA_RPC_PRIVATE for private RPCs, and reported it for RPCs whose
  lock was being requested by the application.
* The existing test set the flag with |=, which hid the bug; use
  set_bit and add a test that APP_NEEDS_LOCK alone isn't reported.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: randomizedcoder

homa_rpc.c

@@ -844,6 +844,6 @@ void homa_rpc_get_info(struct homa_rpc *rpc, struct homa_rpc_info *info)
 	    rpc->msgin.bytes_remaining == 0 &&
 	    skb_queue_len(&rpc->msgin.packets) == 0)
 		info->flags |= HOMA_RPC_RX_READY;
-	if (rpc->flags & RPC_PRIVATE)
+	if (test_bit(RPC_PRIVATE, &rpc->flags))
 		info->flags |= HOMA_RPC_PRIVATE;
 }

test/unit_homa_rpc.c

@@ -1572,7 +1572,18 @@ TEST_F(homa_rpc, homa_rpc_get_info__HOMA_RPC_PRIVATE)
 			self->server_port, self->client_id, 5000, 20000);
 	struct homa_rpc_info info;
 
-	crpc->flags |= RPC_PRIVATE;
+	set_bit(RPC_PRIVATE, &crpc->flags);
 	homa_rpc_get_info(crpc, &info);
 	EXPECT_EQ(HOMA_RPC_PRIVATE, info.flags);
 }
+TEST_F(homa_rpc, homa_rpc_get_info__APP_NEEDS_LOCK_is_not_private)
+{
+	struct homa_rpc *crpc = unit_client_rpc(&self->hsk,
+			UNIT_OUTGOING, self->client_ip, self->server_ip,
+			self->server_port, self->client_id, 5000, 20000);
+	struct homa_rpc_info info;
+
+	set_bit(APP_NEEDS_LOCK, &crpc->flags);
+	homa_rpc_get_info(crpc, &info);
+	EXPECT_EQ(0, info.flags);
+}