Do they call black people African-Americans in the UK?
What do the Brits call blacks whose ancestry is straight out of Africa to England?
No, unless you want to get anything from a dirty look to a punch in the nose by the person you're calling "African-American".
What do the Brits call blacks whose ancestry is straight out of Africa to England?
Usually just "Black" or "African", in most other cases "Nigerian", "Ghanaian", or whatever country they have ancestry in.