Revert "bareudp: Pull inner IP header in bareudp_udp_encap_recv()."

This reverts commit 2099b709 which is
commit 45fa29c8 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: Ib580a5d456d2c3664b73bdbb295ae63791f726c2
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>