MINOR: quic: Avoid cc priv buffer overflow.

MINOR: quic: Avoid cc priv buffer overflow.

Add two initcall callback with BUG_ON_HOT() to newro and cubic modules to
ensure there is no buffer overflow when accessing the private data of
these congestion control algorithm state structures. This is to ensure
that further modifications about these data structures will not
lead to surprises. At this time there is no possible buffer overflow.