PR feedback: add more wycheproof ECDH test cases

Co-authored-by: Sean Andersen <6730974+andozw@users.noreply.github.com>

Author: RandomLattice

src/modules/ecdh/tests_impl.h

@@ -170,8 +170,7 @@ static void test_ecdh_wycheproof(void) {
 
         expected_result = testvectors[t].expected_result;
 
-        /* fail if public key is valid, but doesn't parse */
-        CHECK(parsed_ok || expected_result == 0);
+        CHECK(parsed_ok == expected_result);
 
         if (!parsed_ok && expected_result == 0) {
             continue;