LMSDevice: Fix initial timestamp offset of 2500

ts_initial must not point to the timestamp of the first sample
in the last "flush" sample buffer, but to the first timestamp we
expect in the next buffer.

Change-Id: I23af62870544d4c6cf5f6e2d6578936603bceb91
diff --git a/Transceiver52M/device/lms/LMSDevice.cpp b/Transceiver52M/device/lms/LMSDevice.cpp
index 3b2ce5e..9cfa96d 100644
--- a/Transceiver52M/device/lms/LMSDevice.cpp
+++ b/Transceiver52M/device/lms/LMSDevice.cpp
@@ -345,7 +345,7 @@
 			return false;
 		}
 
-		ts_initial = rx_metadata.timestamp;
+		ts_initial = rx_metadata.timestamp + len;
 	}
 
 	LOG(INFO) << "Initial timestamp " << ts_initial << std::endl;