You don't need the inner sets of () in your case, he just put them there for readability. Boolean operators have an order of precedence, && before ||. So if you have a complex if statement you'll need to use ( ) to control the order of operations of the boolean statement.
Foe example.
(x == a || (x == b && y == a)) is the same as (x == a || x == b && y == a).
However, those are both different from ((x == a || x == b) && y == a)