Revert "net: use unrcu_pointer() helper"

This reverts commit ad3c88eb which is
commit b4cb4a13 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I52249fb612f453572407a5a8098699d69d23348b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>