[NET]: Add sock_create_lite()

[NET]: Add sock_create_lite()

The purpose of this is to allow sockets created by the kernel in this way
to be passed through the LSM socket creation hooks and be labeled and
mediated in the same manner as other sockets.

This patches addresses a class of potential issues with LSMs, where such
sockets will not be labeled correctly (if at all), or mediated during
creation.  Under SELinux, it fixes a specific bug where RPC sockets
created by the kernel during TCP NFS serving are unlabeled.