Factor shell prompt into overwrite file.

kern/main/menu.c

@@ -41,6 +41,7 @@
 #include <sfs.h>
 #include <syscall.h>
 #include <test.h>
+#include <overwrite.h>
 #include "opt-sfs.h"
 #include "opt-net.h"
 
@@ -724,7 +725,11 @@ menu(char *args)
 	menu_execute(args, 1);
 
 	while (1) {
-		kprintf("OS/161 kernel [? for menu]: ");
+		/*
+		 * Defined in overwrite.h. If you want to change the kernel prompt, please
+		 * do it in that file. Otherwise automated test testing will break.
+		 */
+		kprintf(KERNEL_PROMPT);
 		kgets(buf, sizeof(buf));
 		menu_execute(buf, 0);
 	}