If we're going to unmap a folio, we have to be sure to unmap the entire
folio, not just the part of it which lies after the search index.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>