title: FT_SetFlowControl works without valid enumeration value
body: <p>I have seen </p>
  
  <pre><code>FT_STATUS 
  FT_SetFlowControl 
  (FT_HANDLE ftHandle, USHORT usFlowControl, UCHAR uXon,UCHAR uXoff)
  </code></pre>
  
  <p>function works with a random value for usFlowControl other than "Must be one of FT_FLOW_NONE, FT_FLOW_RTS_CTS, FT_FLOW_DTR_DSR or FT_FLOW_XON_XOFF", but only in some instances. is this a known issue. is it a whim? please help.</p>