Remove always-on logging from fuzz targets (#878)

Now that the `cargo fuzz` tooling is better, it is easier to reproduce failures,
and we don't need to be super paranoid about logging here.

fuzz/fuzz_targets/api_calls.rs

@@ -1,27 +1,8 @@
 #![no_main]
 
 use libfuzzer_sys::fuzz_target;
-use std::sync::Once;
 use wasmtime_fuzzing::{generators::api::ApiCalls, oracles};
 
 fuzz_target!(|api: ApiCalls| {
-    static INIT_LOGGING: Once = Once::new();
-    INIT_LOGGING.call_once(|| env_logger::init());
-
-    log::debug!(
-        "If this fuzz test fails, here is a regression tests:
-```
-#[test]
-fn my_regression_test() {{
-    use wasmtime_fuzzing::generators::{{
-        api::{{ApiCall::*, ApiCalls}},
-        WasmOptTtf,
-    }};
-    wasmtime_fuzzing::oracles::make_api_calls({:#?});
-}}
-```",
-        api
-    );
-
     oracles::make_api_calls(api);
 });