[NFC][VecOps] Remove unnecessary namespace qualifiers
[NFC][VecOps] Remove unnecessary namespace qualifiers

It makes the test code more readable.

olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root