API CHANGE: Reorder parameters for some APIs.

The APIs that have changed are those that take an output pointer and an
input count in the format of "some_read_function(handle, pBuf, count)".

The updated APIs include:
  * mal_decoder_read_pcm_frames()
  * mal_pcm_converter_read()

Some APIs are scheduled to be replaced in a future version so I have
decided not to replace this at this time since it will be a waste of
time to do so.

examples/simple_playback.c

@@ -17,7 +17,7 @@ void data_callback(mal_device* pDevice, void* pOutput, const void* pInput, mal_u
         return;
     }
 
-    mal_decoder_read_pcm_frames(pDecoder, frameCount, pOutput);
+    mal_decoder_read_pcm_frames(pDecoder, pOutput, frameCount);
 
     (void)pInput;
 }