[PATCH] hfs: set correct create date for links

HFS+ also requires the correct creation date so recent version of OS X
recognize it as link.
Improve link handling:
- if something is wrong with the link, ignore the link attribute and treat
  it as regular file (this also fixes a missing unlock during lookup).
- check for incorrect link counts during unlink.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>