If we fail to find init, print out the search path used. This helps

differentiate between one of three different scenarios:

1.  No init.
2.  Path to init munged by an incorrect loader configuration.
3.  Root file system not mounted.

Reviewed-by:  billf

sys/kern/init_main.c

@@ -609,6 +609,6 @@ start_init(dummy)
 			printf("exec %.*s: error %d\n", (int)(next - path), 
 			    path, error);
 	}
-	printf("init: not found\n");
+	printf("init: not found in path %s\n", init_path);
 	panic("no init");
 }