TAKE 988255 - fix instant oops with tracing enabled

[lachlan@xxxxxxx (Lachlan McIlroy)]

fix instant oops with tracing enabled

We can only read inode->i_count if the inode is actually there and not
a NULL pointer.  This was introduced in one of the recent sync patches.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Date:  Tue Oct 14 12:17:19 EST 2008
Workarea:  redback.melbourne.sgi.com:/home/lachlan/isms/2.6.x-sync
Inspected by:  lachlan
Author:  lachlan

The following file(s) were checked into:
  longdrop.melbourne.sgi.com:/isms/linux/2.6.x-xfs-melb


Modid:  xfs-linux-melb:xfs-kern:32315a
fs/xfs/linux-2.6/xfs_vnode.c - 1.164 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.6/xfs_vnode.c.diff?r1=text&tr1=1.164&r2=text&tr2=1.163&f=h
        - fix instant oops with tracing enabled