Revert "bpf: Fix reference state management for synchronous callbacks"

This reverts commit 4ed51550 which is
commit 9d9d00ac upstream.

It breaks the Android kernel ABI and is not needed for normal Android
systems so it is safe to remove.  If it is needed in the future, it can
be brought back in an abi-safe way.

Bug: 161946584
Change-Id: Idc9e43f0bc47de086cefd5cd572ce8295bbb7b08
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>