Use printf format macro here

src/NDS.cpp

@@ -3570,7 +3570,7 @@ void ARM9IOWrite32(u32 addr, u32 val)
         }
 
     // NO$GBA debug register "Char Out"
-    case 0x04FFFA1C: printf("%lc", val); return;
+    case 0x04FFFA1C: printf("%" PRIu32, val); return;
     }
 
     if (addr >= 0x04000000 && addr < 0x04000060)