```
Change refcounting scheme to a more idiomatic approach: every
secasvar object keeps a ref to SAH which is only released when
the object goes away.
Plugs panics of the form:
panic: esp_input_cb: Unexpected address family: 0 saidx=0xfffffd001832a330
```
A validated this is the issue by neglecting to actually free anything on stock kernel and instead poisoning address family with a dedicated value, which did start showing up.