Description

   This routine destroys the specified condition variable attributes
   object. Call this routine when a condition variable attributes
   object will no longer be referenced.

   Condition variables that were created using this attributes
   object are not affected by the destruction of the condition
   variable attributes object.

   The results of calling this routine are unpredictable if the
   value specified by the attr argument refers to a condition
   variable attributes object that does not exist.