Fix an unused variable warning on non-DEBUG builds introduced by
commit 7561d27e ("xfs: buffer lru reference count error injection
tag").
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>