VSOCK: get rid of EXPORT_SYMTAB

This is the default behavior for a looooooong time.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
VSOCK: get rid of vsock_version.h

There isn't really a need to have a separate file for it.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>