add a missing comma (#651)

include/task.h

diff --git a/include/task.h b/include/task.h
index 054f436..702f74d 100644
--- a/include/task.h
+++ b/include/task.h
@@ -1664,7 +1664,7 @@
 /**
  * task.h
  * @code{c}
- * void vApplicationStackOverflowHook( TaskHandle_t xTask char *pcTaskName);
+ * void vApplicationStackOverflowHook( TaskHandle_t xTask, char *pcTaskName);
  * @endcode
  *
  * The application stack overflow hook is called when a stack overflow is detected for a task.