sparse test: fix for 64k page size

this test failed on Debian's CI on ppc64el, because the page size is
64k there, which means the block size on tmpfs is as well, so attempting
to create 32k big holes cannot work.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>

src/builder.rs

@@ -1114,8 +1114,9 @@ impl<W: Write> Drop for Builder<W> {
 mod tests {
     use super::*;
 
-    /// Should be multiple of 4KiB on ext4, multiple of 32KiB on FreeBSD/UFS.
-    const SPARSE_BLOCK_SIZE: u64 = 32768;
+    /// Should be multiple of 4KiB on ext4, multiple of 32KiB on FreeBSD/UFS, multiple of 64KiB on
+    /// ppc64el
+    const SPARSE_BLOCK_SIZE: u64 = 64*1024;
 
     #[test]
     fn test_find_sparse_entries() {