netfilter: nfnetlink_{log,queue}: fix information leaks in netlink message

These structs have a "_pad" member.  Also the "phw" structs have an 8
byte "hw_addr[]" array but sometimes only the first 6 bytes are
initialized.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>