Update playback example to include logging.

examples/simple_playback.c

@@ -6,6 +6,13 @@
 
 #include <stdio.h>
 
+void on_log(mal_context* pContext, mal_device* pDevice, const char* message)
+{
+    (void)pContext;
+    (void)pDevice;
+    printf("mini_al: %s\n", message);
+}
+
 // This is the function that's used for sending more data to the device for playback.
 mal_uint32 on_send_frames_to_device(mal_device* pDevice, mal_uint32 frameCount, void* pSamples)
 {
@@ -31,7 +38,7 @@ int main(int argc, char** argv)
     }
 
     mal_context context;
-    if (mal_context_init(NULL, 0, NULL, &context) != MAL_SUCCESS) {
+    if (mal_context_init(NULL, 0, on_log, &context) != MAL_SUCCESS) {
         printf("Failed to initialize context.");
 		drwav_uninit(&wav);
         return -3;