btrfs: Don't BUG_ON alloc_path errors in btrfs_truncate_inode_items

I moved the path allocation up a few lines to the top of the function so
that we couldn't get into the state where we've dropped delayed items and
the extent cache but fail due to -ENOMEM.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
1 file changed