Fix Klocwork#1093: Infinite loop.

* Added comment to verify requirement for infinite loop.

Signed-off-by: Kevin Moloney <[email protected]>

Author: Kevin Moloney

cores/arduino/CDCSerialClass.cpp

@@ -120,7 +120,8 @@ int CDCSerialClass::read( void )
 
 void CDCSerialClass::flush( void )
 {
-    while (_tx_buffer->tail != _tx_buffer->head) {
+    while (_tx_buffer->tail != _tx_buffer->head) { /* This infinite loop is intentional
+						      and requested by design */
 	    delayMicroseconds(1);
     }
 }