comment out obsolete ext2 code

This patch comments out code in ext2 which is obsolete, or was never used in the first place (i.e. future vision stuff, etc). In particular, the inode->i_attr_flags field is not used anywhere else in the kernel, and it is only set, but not referenced in the ext2 code. It could probably be deleted entirely (saving 4 bytes in struct inode).

Similarly, the ext2_notify_change() function is not currently in use (but it may be needed at some time in the future). However, per previous discussions with Stephen on ext2-devel, the 2.4 code is buggy (2.2 code was fixed), so even though it is currently unused I have fixed it. The brokenness in question also relates to i_attr_flags, so it could also be deleted entirely if that is the goal.

There are a couple of other obsolete bits not removed by this patch, namely i_osync, and i_new_inode in ext2_inode_info. Another day...

Cheers, Andreas

Andreas Dilger  \ "If a man ate a pound of pasta and a pound of antipasto,
                 \  would they cancel out, leaving him still hungry?"
http://www-mddsp.enel.ucalgary.ca/People/adilger/               -- Dogbert