Fix M512 comment (#19108)

Marlin/Configuration.h

@@ -1667,7 +1667,7 @@
   #define PASSWORD_LENGTH 4                 // (#) Number of digits (1-9). 3 or 4 is recommended
   #define PASSWORD_ON_STARTUP
   #define PASSWORD_UNLOCK_GCODE             // Unlock with the M511 P<password> command. Disable to prevent brute-force attack.
-  #define PASSWORD_CHANGE_GCODE             // Change the password with M512 P<old> N<new>.
+  #define PASSWORD_CHANGE_GCODE             // Change the password with M512 P<old> S<new>.
   //#define PASSWORD_ON_SD_PRINT_MENU       // This does not prevent gcodes from running
   //#define PASSWORD_AFTER_SD_PRINT_END
   //#define PASSWORD_AFTER_SD_PRINT_ABORT