xfs_dir2_node_trim_free can return with setting the rvalp argument
pointer. Initialize it to 0 at the beginning of the function and
only update it to 1 if we succeeded trimming a freespace block.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>