elf: Change ldconfig auxcache magic number (bug 32231)

elf: Change ldconfig auxcache magic number (bug 32231)

In commit c628c2296392ed3bf2cb8d8470668e64fe53389f (elf: Remove
ldconfig kernel version check), the layout of auxcache entries
changed because the osversion field was removed from
struct aux_cache_file_entry.  However, AUX_CACHEMAGIC was not
changed, so existing files are still used, potentially leading
to unintended ldconfig behavior.  This commit changes AUX_CACHEMAGIC,
so that the file is regenerated.

Reported-by: DJ Delorie <dj@redhat.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>