delete module's redundant print_status()

- we can already get the running status from ModuleBase and the other misc information is already available through perf or uORB

src/drivers/safety_button/SafetyButton.cpp

@@ -199,14 +199,6 @@ SafetyButton::custom_command(int argc, char *argv[])
 	return print_usage("unknown command");
 }
 
-int
-SafetyButton::print_status()
-{
-	PX4_INFO("Safety State (from button): %s", _safety_btn_off ? "off" : "on");
-
-	return 0;
-}
-
 int
 SafetyButton::print_usage(const char *reason)
 {