Fix unused parameter warnings.

src/iterator.c

@@ -966,4 +966,8 @@ void cdiIterator_delete(CdiIterator* me)
     }
 }
 
-void baseIterDestruct(CdiIterator* me) { /*currently empty, but that's no reason not to call it*/ }
+void baseIterDestruct(CdiIterator* me)
+{
+  /*currently empty, but that's no reason not to call it*/
+  (void)me;
+}

src/iterator_fallback.c

@@ -195,6 +195,7 @@ int cdiFallbackIterator_levelType(CdiIterator* super, int levelSelector, char**
 {
   CdiFallbackIterator* me = (CdiFallbackIterator*)super;
   int zaxisId = vlistInqVarZaxis(me->vlistId, me->curVariable);
+  (void)levelSelector;
   #define copyString(outPointer, function) do \
     { \
       if(outPointer) \

src/referenceCounting.c

@@ -25,4 +25,8 @@ void cdiRefObject_release(CdiReferencedObject* me)
     }
 }
 
-void cdiRefObject_destruct(CdiReferencedObject* me) { /* Empty for now, but that's no reason not to call it! */ }
+void cdiRefObject_destruct(CdiReferencedObject* me)
+{
+  (void)me;
+  /* Empty for now, but that's no reason not to call it! */
+}