Update (bug fix?) in duplex.cpp test program

tests/duplex.cpp

@@ -105,6 +105,7 @@ int main( int argc, char *argv[] )
   RtAudio::StreamOptions options;
   //options.flags |= RTAUDIO_NONINTERLEAVED;
 
+  bufferBytes = bufferFrames * channels * sizeof( MY_TYPE );
   try {
     adac.openStream( &oParams, &iParams, FORMAT, fs, &bufferFrames, &inout, (void *)&bufferBytes, &options );
   }
@@ -113,8 +114,6 @@ int main( int argc, char *argv[] )
     exit( 1 );
   }
 
-  bufferBytes = bufferFrames * channels * sizeof( MY_TYPE );
-
   // Test RtAudio functionality for reporting latency.
   std::cout << "\nStream latency = " << adac.getStreamLatency() << " frames" << std::endl;