fuzz: Use ConsumeUInt256 helper to simplify rolling_bloom_filter fuzz test

src/test/fuzz/rolling_bloom_filter.cpp

@@ -36,13 +36,10 @@ FUZZ_TARGET(rolling_bloom_filter)
                 assert(present);
             },
             [&] {
-                const std::optional<uint256> u256 = ConsumeDeserializable<uint256>(fuzzed_data_provider);
-                if (!u256) {
-                    return;
-                }
-                (void)rolling_bloom_filter.contains(*u256);
-                rolling_bloom_filter.insert(*u256);
-                const bool present = rolling_bloom_filter.contains(*u256);
+                const uint256 u256{ConsumeUInt256(fuzzed_data_provider)};
+                (void)rolling_bloom_filter.contains(u256);
+                rolling_bloom_filter.insert(u256);
+                const bool present = rolling_bloom_filter.contains(u256);
                 assert(present);
             },
             [&] {