bcache: Kill op->cl

This isn't used for waiting asynchronously anymore - so this is a fairly
trivial refactoring.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/btree.h b/drivers/md/bcache/btree.h
index 3f820b6..34ee535 100644
--- a/drivers/md/bcache/btree.h
+++ b/drivers/md/bcache/btree.h
@@ -237,8 +237,6 @@
 /* Recursing down the btree */
 
 struct btree_op {
-	struct closure		cl;
-
 	/* Btree level at which we start taking write locks */
 	short			lock;
 
@@ -253,7 +251,11 @@
 	BKEY_PADDED(replace);
 };
 
-void bch_btree_op_init_stack(struct btree_op *);
+static inline void bch_btree_op_init(struct btree_op *op, int write_lock_level)
+{
+	memset(op, 0, sizeof(struct btree_op));
+	op->lock = write_lock_level;
+}
 
 static inline void rw_lock(bool w, struct btree *b, int level)
 {