Fix some issues with the no exception build

include/continuable/detail/transforms.hpp

@@ -100,6 +100,8 @@ public:
     !defined(CONTINUABLE_WITH_NO_EXCEPTIONS)
     promise_.set_exception(error);
 #else
+    (void)error;
+
     // Can't forward a std::error_condition or custom error type
     // to a std::promise. Handle the error first in order
     // to prevent this trap!

test/unit-test/test-continuable-base-errors.cpp

@@ -50,10 +50,12 @@ static auto supply_test_exception() {
 }
 #else
 struct my_error_category : std::error_category {
-  const char* name() const override noexcept {return "generic name"}
+  const char* name() const noexcept override {
+    return "generic name";
+  }
 
   std::string message(int) const override {
-    return "generic"
+    return "generic";
   }
 };