[GFS2] gfs2_lookupi() uninitialised var fix

fs/gfs2/inode.c: In function 'gfs2_lookupi':
fs/gfs2/inode.c:392: warning: 'error' may be used uninitialized in this function

Looks like a real bug to me.

Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>