Deterministic toString check doesn't work with ternary

[jwaataja]

The check performed by @RequiresDetToString sometimes prints an error when it shouldn't, such as in this class,

import org.checkerframework.checker.determinism.qual.*;

public class C {
    public static void f() {
        System.out.printf("%s", true ? "" : "");
    }
}

I get the error

C.java:5: error: [nondeterministic.tostring] java.lang.Object does not override toString() deterministically
        System.out.printf("%s", true ? "" : "");
                         ^

This doesn't happen if we just write System.out.printf("%s", "");. It must have something to do with the ternary operator in this case.