Revert "net: skb: add pskb_network_may_pull_reason() helper"

This reverts commit 14f0d3c7 which is
commit 454bbde8 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: Ib334d1e8d1e5ccc08d5e6e3f39737e010fb8f1d1
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>