ocfs2: dereferencing freed pointers in ocfs2_reflink()

The code at the "out" label assumes that "default_acl" and "acl" are NULL,
but actually the pointers can be NULL, unitialized, or freed.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>