Use getter

Marlin/src/feature/e_parser.h

@@ -79,6 +79,9 @@ public:
 
   static void update(State &state, const uint8_t c);
 
+  static bool isEnabled() { return enabled;}
+
+private:
   static bool enabled;
 };
 

Marlin/src/gcode/host/M876.cpp

@@ -35,7 +35,7 @@
  * M876: Handle Prompt Response
  */
 void GcodeSuite::M876() {
-  if(TERN1(EMERGENCY_PARSER, emergency_parser.enabled))
+  if(TERN1(EMERGENCY_PARSER, emergency_parser.isEnabled()))
     if (parser.seenval('S')) hostui.handle_response((uint8_t)parser.value_int());
 
 }