When CONFIG_XFS_POSIX_ACL is not set "xfs_check_acl" is #defined
to NULL - which breaks the code attempting to add a tracepoint
on this function.

Only define the tracepoint when the function exists.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>