btrfs: remove cache only arguments from defrag path

The entry point at the defrag ioctl always sets "cache only" to 0;
the codepaths haven't run for a long time as far as I can
tell.  Chris says they're dead code, so remove them.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index deb7f66..1a79087 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2738,7 +2738,7 @@
 	path->keep_locks = 1;
 
 	ret = btrfs_search_forward(root, &min_key, &max_key,
-				   path, 0, trans->transid);
+				   path, trans->transid);
 
 	/*
 	 * we didn't find anything from this transaction, see if there
@@ -3680,7 +3680,7 @@
 	while (1) {
 		ins_nr = 0;
 		ret = btrfs_search_forward(root, &min_key, &max_key,
-					   path, 0, trans->transid);
+					   path, trans->transid);
 		if (ret != 0)
 			break;
 again: