cifs_idmap: Fix warning address-of-packed-member
    
    Packed attribute on a structure implies the alignment of the structure
    is 1 byte. And uint32_t/uid_t is usually aligned to 4 bytes.
    
      CC       src/lib/cifs_idmap_sss/cifs_idmap_sss_la-cifs_idmap_sss.lo
    src/lib/cifs_idmap_sss/cifs_idmap_sss.c: In function ‘sss_sid_to_id’:
    src/lib/cifs_idmap_sss/cifs_idmap_sss.c:221:47: error: taking address of packed
        member of ‘struct cifs_uxid’ may result in an unaligned pointer
        value [-Werror=address-of-packed-member]
      221 |     err = sss_nss_getidbysid(sid, (uint32_t *)&cuxid->id.uid, &id_type);
          |
    
    Merges: https://pagure.io/SSSD/sssd/pull-request/3950