aya/xtask
Andrew Stoycos 72cf497448 aya/maps: fix libbpf_pin_by_name, add pin() api
- Aligns with libbpf for the special LIBBPF_PIN_BY_NAME
map flag. Specifically if the flag is provided without a pin path
default to "/sys/fs/bpf".

- Adds new `maps_mut()` API to the BpfManager to allow us to iterate though
and pin all of maps at the same time.

- Adds new pin()/unpin() api to Maps so they
can be generically pinned AFTER load.

- Adds macro for pinning explicit map types in aya.
Convert all explicit map types "inner" field to be
pub crate in order to facilitate this.

Signed-off-by: Andrew Stoycos <astoycos@redhat.com>
..
libbpf@a2258003f2 xtask: move libbpf submodule
public-api aya/maps: fix libbpf_pin_by_name, add pin() api
src xtask: extract `Errors` type
Cargo.toml Cargo.toml: Remove default-features settings