Transceiver52M: Delay UHD messaging registration until after start

We want to push UHD logs to the OpenBTS logging system, but most
device errors occur at startup, so keep the output on stdout until
after device initialization. That way obvious errors are easily
viewable before seeing the useless TRX timeout message.

Signed-off-by: Thomas Tsou <tom@tsou.cc>

Transceiver52M/UHDDevice.cpp

@@ -521,9 +521,6 @@ bool uhd_device::parse_dev_type()
 
 int uhd_device::open(const std::string &args)
 {
-	// Register msg handler
-	uhd::msg::register_handler(&uhd_msg_handler);
-
 	// Find UHD devices
 	uhd::device_addr_t addr(args);
 	uhd::device_addrs_t dev_addrs = uhd::device::find(addr);
@@ -644,6 +641,9 @@ bool uhd_device::start()
 
 	setPriority();
 
+	// Register msg handler
+	uhd::msg::register_handler(&uhd_msg_handler);
+
 	// Start asynchronous event (underrun check) loop
 	async_event_thrd.start((void * (*)(void*))async_event_loop, (void*)this);