Fix command parameters offset

Author: RoboMagus

Firmware/Marlin_main.cpp

@@ -6526,7 +6526,7 @@ SERIAL_PROTOCOLPGM("\n\n");
     */
     case 118: {
         bool hasE = false, hasA = false;
-        char *p = strchr_pointer;
+        char *p = strchr_pointer + 4;
 
         for (uint8_t i = 2; i--;) {
           // A1, E1, and Pn are always parsed out