wstd::http_server: don't panic after setting responder.fail (#117)

passing the error out to the host via responder.fail is all thats needed
here - the host is responsible for reporting that error, so theres no
need for the guest to panic afterwards.

So, Responder::fail no longer needs a return value, and the macro no
longer needs to unwrap it

Author: pchickey

macro/src/lib.rs

@@ -138,9 +138,9 @@ pub fn attr_macro_http_server(_attr: TokenStream, item: TokenStream) -> TokenStr
                     match ::wstd::http::request::try_from_incoming(request) {
                         Ok(request) => match __run(request) #run_await {
                             Ok(response) => { responder.respond(response).await.unwrap() },
-                            Err(err) => responder.fail(err).unwrap(),
+                            Err(err) => responder.fail(err),
                         }
-                        Err(err) => responder.fail(err).unwrap(),
+                        Err(err) => responder.fail(err),
                     }
                 })
             }

src/http/server.rs

@@ -77,12 +77,11 @@ impl Responder {
 
     /// This is used by the `http_server` macro.
     #[doc(hidden)]
-    pub fn fail(self, err: Error) -> Result<(), Error> {
+    pub fn fail(self, err: Error) {
         let e = match err.downcast_ref::<ErrorCode>() {
             Some(e) => e.clone(),
             None => ErrorCode::InternalError(Some(format!("{err:?}"))),
         };
         ResponseOutparam::set(self.outparam, Err(e));
-        Err(err)
     }
 }