SKIP_IF_BPF_SUPPORTED is always an early return

As a side effect we end up deleting a bunch of stuff that is no longer
used and would otherwise cause compile warnings and thus errors.

Test: builds, atest, TreeHugger
Bug: 167500195
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1643cb5bc2ec92cfe0753dc685a65ebc8e0f6ab2