False positive in unnecessary_unwrap

[JohnTitor]

@flip1995 pointed out this FP in unnecessary_unwrap:

macro_rules! m {
    ($a:expr, $b:expr) => {
         if $a {
              $b;
         }
    }
}

let x: Option<u32> = Some(42);
m!(x.is_some(), x.unwrap());

(playground)

We should also cover this case, it's a follow-up of #5132.

Originally posted by @flip1995 in #5132 (comment)