Patch from Manfred Spraul

Use a local counter instead of the global 'event' variable for the
readdir() optimization.

Depends on patch-event-II

Background:
  The only user of i_version and f_version in ext2 is
  ext2_readdir(). As an optimization, ext2 performs the
  validation of the start position for readdir() only if
        flip->f_version != inode->i_version.
  If there was no llseek and no directory change since the
  last readdir() call, then f_pos can be trusted.
  f_version is set to 0 in get_empty_flip and during llseek.
  Right now, i_version set to ++event during ext2_read_inode
  and commit_chunk, i.e. at inode creation and if a directory
  is changed.
  Initializing i_version to 1, and updating with i_version++
  achieves the same effect, without the need of a global variable.
  Global uniqueness is not required, there are no other uses
  of [if]_version in ext2.

Change relative to the patch you have right now:
i_version is initialized to 1 instead of 0. For ext2 it's doesn't
matter [there is always a valid 'len' value at the beginning of a
directory data block], but it's cleaner.