nilfs2: use empty_aops for gc-inodes

#include "dat.h"

#include "ifile.h"

static const struct address_space_operations def_gcinode_aops = {

};

/*

 * nilfs_gccache_submit_read_data() - add data buffer and submit read request

 * @inode - gc inode

	inode->i_mode = S_IFREG;

	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);

	inode->i_mapping->a_ops = &def_gcinode_aops;

	inode->i_mapping->a_ops = &empty_aops;

	inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;

	ii->i_flags = 0;