btrfs: Remove fs_info from run_delayed_extent_op

This function is always called with a valid transaction handle so
fs_info can be referenced from there. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>