Add default case for non-exhaustive switch statement

Author: trevorknight

code/src/iamf_dec/vlogging_tool_sr.c

@@ -249,6 +249,8 @@ int write_postfix(LOG_TYPE type, char* buf) {
     case LOG_DECOP:
       len = sprintf(buf, "##\n");
       break;
+    default:
+      break;
   }
 
   return len;