bcache: Disable broken btree fuzz tester

Reported-by: <sasha.levin@oracle.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>

drivers/md/bcache/debug.c

@@ -409,7 +409,9 @@ void bch_debug_init_cache_set(struct cache_set *c)
 
 #endif
 
-#ifdef CONFIG_BCACHE_DEBUG
+/* Fuzz tester has rotted: */
+#if 0
+
 static ssize_t btree_fuzz(struct kobject *k, struct kobj_attribute *a,
 			  const char *buffer, size_t size)
 {
@@ -552,7 +554,7 @@ void bch_debug_exit(void)
 int __init bch_debug_init(struct kobject *kobj)
 {
 	int ret = 0;
-#ifdef CONFIG_BCACHE_DEBUG
+#if 0
 	ret = sysfs_create_file(kobj, &ksysfs_fuzz.attr);
 	if (ret)
 		return ret;