Revert "tcp: add annotations around sk->sk_shutdown accesses"

This reverts commit 35e4f2bc.  It is
part of a series that breaks the kernel abi for Android.  For this
kernel tree, we do not care so much about KASAN, so it's not a big issue
to revert.  If it is needed in the future, it can be brought back in an
abi-safe way.

Bug: 161946584
Change-Id: I0d17fa20bc0f80f72d89fc0553667155484f2282
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>