Revert "udp: annotate data-races around udp->encap_type"

This reverts commit 158b71f3 which is
commit 70a36f57 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: I516d935c83a8731f077b5b4e72e762c8a9a63bd1
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>