libmbim-glib,net-port-manager: use unaligned netlink attribute length
Removes the warning
[ 120.780599] netlink: 'ModemManager': attribute type 1 has an invalid length.
caused by using an incorrect aligned length of 8 for the 16 bit IFLA_VLAN_ID attribute instead of the expected 6.
Fixes: b2b4b069 ("libmbim-glib,device: new link add/delete operations") Signed-off-by: Bjørn Mork bjorn@mork.no