Fix example for ex_unit assertion (#6608)
Fix example for ex_unit assertion (#6608)

This code example used variables `one` and `two` that weren't previously initialized, and don't match the assertion result message.
kelvinst/elixir,ggcampinho/elixir,antipax/elixir,kimshrier/elixir,kimshrier/elixir,antipax/elixir,gfvcastro/elixir,joshprice/elixir,beedub/elixir,kelvinst/elixir,elixir-lang/elixir,ggcampinho/elixir,gfvcastro/elixir,beedub/elixir,pedrosnk/elixir,michalmuskala/elixir,lexmag/elixir,pedrosnk/elixir,lexmag/elixir