Btrfs: remove tree_search() in extent_map.c

This patch removes tree_search() in extent_map.c because it is not called by
anything.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/extent_map.c

@@ -155,20 +155,6 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
 	return NULL;
 }
 
-/*
- * look for an offset in the tree, and if it can't be found, return
- * the first offset we can find smaller than 'offset'.
- */
-static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
-{
-	struct rb_node *prev;
-	struct rb_node *ret;
-	ret = __tree_search(root, offset, &prev, NULL);
-	if (!ret)
-		return prev;
-	return ret;
-}
-
 /* check to see if two extent_map structs are adjacent and safe to merge */
 static int mergable_maps(struct extent_map *prev, struct extent_map *next)
 {