nilfs2: nuke write_super from comments

The '->write_super' superblock method is gone, and this patch removes all the
references to 'write_super' from ntfs.

Cc: KONISHI Ryusuke <[e-mail]>
Signed-off-by: Artem Bityutskiy <[e-mail]>
Signed-off-by: Al Viro <[e-mail]>

fs/nilfs2/super.c

···
 	.alloc_inode    = nilfs_alloc_inode,
 	.destroy_inode  = nilfs_destroy_inode,
 	.dirty_inode    = nilfs_dirty_inode,
-	/* .write_inode    = nilfs_write_inode, */
-	/* .drop_inode	  = nilfs_drop_inode, */
 	.evict_inode    = nilfs_evict_inode,
 	.put_super      = nilfs_put_super,
-	/* .write_super    = nilfs_write_super, */
 	.sync_fs        = nilfs_sync_fs,
 	.freeze_fs	= nilfs_freeze,
 	.unfreeze_fs	= nilfs_unfreeze,
 	.statfs         = nilfs_statfs,
 	.remount_fs     = nilfs_remount,
-	/* .umount_begin */
 	.show_options = nilfs_show_options
 };
 

fs/nilfs2/the_nilfs.h

···
 	 * used for
 	 * - loading the latest checkpoint exclusively.
 	 * - allocating a new full segment.
-	 * - protecting s_dirt in the super_block struct
-	 *   (see nilfs_write_super) and the following fields.
 	 */
 	struct buffer_head     *ns_sbh[2];
 	struct nilfs_super_block *ns_sbp[2];