netlink_delinarize: fix payload dependency killing of link layer dependencies

netlink_delinarize: fix payload dependency killing of link layer dependencies

payload_dependency_kill() does not properly handle dependencies for link
layer expressions. Since those dependencies are logically defined on an
even lower layer (device layer), we don't have a payload base for them,
meaning they will use PROTO_BASE_INVALID, which is skipped.

So instead of storing the payload base on which the dependency is defined,
we store the base of the layer for which the dependency applies, meaning
dependencies defined by the device layer will properly work.

This fixes killing the dependency of ether saddr, instead of

iiftype ether ether ether saddr ...

we now only display

ether saddr ...

Signed-off-by: Patrick McHardy <kaber@trash.net>