Revert "bpf, sockmap: Wake up polling after data copy"

This reverts commit dd628fc6.

It breaks the Android KABI and will be brought back at a later time when
it is safe to do so.

Bug: 161946584
Change-Id: Iceb2053c9440a9b52e1d1d331bdd4fb9f8d649c9
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>