cutils: Fix size_to_str() on 32-bit platforms

When extracting a human-readable size formatter, we changed 'uint64_t
div' pre-patch to 'unsigned long div' post-patch. Which breaks on
32-bit platforms, resulting in 'inf' instead of intended values larger
than 999GB.

Fixes: 22951aaa
CC: qemu-stable@nongnu.org
Reported-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

util/cutils.c

@@ -825,7 +825,7 @@ const char *qemu_ether_ntoa(const MACAddr *mac)
 char *size_to_str(uint64_t val)
 {
     static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
-    unsigned long div;
+    uint64_t div;
     int i;
 
     /*