Merge pull request #4349 from jbrazio/gcc-bark-bark

Removes some minor GCC warnings

Marlin/Marlin_main.cpp

 inline void gcode_M77() { print_job_timer.stop(); }
 
 #if ENABLED(PRINTCOUNTER)
-  /*+
+  /**
    * M78: Show print statistics
    */
   inline void gcode_M78() {