bcache: Rename/shuffle various code around

More work to disentangle bset.c from the rest of the code:

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c
index 955fa1d3..5a78137 100644
--- a/drivers/md/bcache/debug.c
+++ b/drivers/md/bcache/debug.c
@@ -123,7 +123,8 @@
 	for (i = (start);						\
 	     (void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\
 	     i->seq == (start)->seq;					\
-	     i = (void *) i + set_blocks(i, b->c) * block_bytes(b->c))
+	     i = (void *) i + set_blocks(i, block_bytes(b->c)) *	\
+		 block_bytes(b->c))
 
 void bch_btree_verify(struct btree *b)
 {