When a small brokerage firm contacted Goldman Sachs Asset Management last week offering to sell $2.8 billion of deeply discounted Venezuelan bonds, the response was a quick “yes.” Buying the bonds for pennies on the dollar was a no-brainer for fund managers in the unit of Goldman Sachs Group Inc., according to people familiar with the matter. Internally, the purchase didn’t receive heightened scrutiny. The two co-heads of the…