Btrfs: remove unused trans in read_block_for_search

@trans is not used at all, this removes it.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.c

@@ -2438,8 +2438,7 @@ noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
  * reada.  -EAGAIN is returned and the search must be repeated.
  */
 static int
-read_block_for_search(struct btrfs_trans_handle *trans,
-		       struct btrfs_root *root, struct btrfs_path *p,
+read_block_for_search(struct btrfs_root *root, struct btrfs_path *p,
 		      struct extent_buffer **eb_ret, int level, int slot,
 		      const struct btrfs_key *key, u64 time_seq)
 {
@@ -2871,8 +2870,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 				goto done;
 			}
 
-			err = read_block_for_search(trans, root, p,
-						    &b, level, slot, key, 0);
+			err = read_block_for_search(root, p, &b, level,
+						    slot, key, 0);
 			if (err == -EAGAIN)
 				goto again;
 			if (err) {
@@ -3015,7 +3014,7 @@ int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
 				goto done;
 			}
 
-			err = read_block_for_search(NULL, root, p, &b, level,
+			err = read_block_for_search(root, p, &b, level,
 						    slot, key, time_seq);
 			if (err == -EAGAIN)
 				goto again;
@@ -5786,7 +5785,7 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 
 		next = c;
 		next_rw_lock = path->locks[level];
-		ret = read_block_for_search(NULL, root, path, &next, level,
+		ret = read_block_for_search(root, path, &next, level,
 					    slot, &key, 0);
 		if (ret == -EAGAIN)
 			goto again;
@@ -5836,7 +5835,7 @@ int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
 		if (!level)
 			break;
 
-		ret = read_block_for_search(NULL, root, path, &next, level,
+		ret = read_block_for_search(root, path, &next, level,
 					    0, &key, 0);
 		if (ret == -EAGAIN)
 			goto again;