bcache: Sparse fixes

Signed-off-by: Kent Overstreet <koverstreet@google.com>
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index f2b2c65..767b3fb 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -130,7 +130,7 @@
 	void *data = (void *) i + 8, *end = end(i);
 
 	crc = bch_crc64_update(crc, data, end - data);
-	return crc ^ 0xffffffffffffffff;
+	return crc ^ 0xffffffffffffffffULL;
 }
 
 static void btree_bio_endio(struct bio *bio, int error)