net: websocket: Fix websocket loop close call

A normal websocket close sequence:
  close(websock) ->
    websocket_close_vmeth() ->
      websocket_disconnect()

close(ctx->sock) called in the function websocket_disconnect()
and cause websocket_close_vmeth() called again.
Finally stack overflow by loop close call.

It's maybe a side-effect by PR #27485

Signed-off-by: Jackie Ja <qazq.jackie@gmail.com>