Fixes #1791: Port Lua Bin Allocator to next:

* Bin Allocator
* Lua memory allocaton fixes
* Simulator memory leak fixes

radio/src/audio_arm.cpp

@@ -274,6 +274,7 @@ void referenceSystemAudioFiles()
         }
       }
     }
+    f_closedir(&dir);
   }
 
   sdAvailableSystemAudioFiles = availableAudioFiles;
@@ -395,6 +396,7 @@ void referenceModelAudioFiles()
         }
       }
     }
+    f_closedir(&dir);
   }
 }