bcache: Btree verify code improvements

Used this fixed code to find and fix the bug fixed by
a4d885097b0ac0cd1337f171f2d4b83e946094d4.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/debug.h b/drivers/md/bcache/debug.h
index 2ede60e..08e116e 100644
--- a/drivers/md/bcache/debug.h
+++ b/drivers/md/bcache/debug.h
@@ -7,7 +7,7 @@
 
 #ifdef CONFIG_BCACHE_DEBUG
 
-void bch_btree_verify(struct btree *, struct bset *);
+void bch_btree_verify(struct btree *);
 void bch_data_verify(struct cached_dev *, struct bio *);
 int __bch_count_data(struct btree *);
 void __bch_check_keys(struct btree *, const char *, ...);
@@ -20,7 +20,7 @@
 
 #else /* DEBUG */
 
-static inline void bch_btree_verify(struct btree *b, struct bset *i) {}
+static inline void bch_btree_verify(struct btree *b) {}
 static inline void bch_data_verify(struct cached_dev *dc, struct bio *bio) {}
 static inline int __bch_count_data(struct btree *b) { return -1; }
 static inline void __bch_check_keys(struct btree *b, const char *fmt, ...) {}