Revert logging change in do_post error path

Remove response body from the post failure log message to avoid
potential breaking changes in log output format.

Author: maxday

src/runtime.cpp

@@ -387,10 +387,7 @@ runtime::post_outcome runtime::do_post(
 
     if (!is_success(aws::http::response_code(http_response_code))) {
         logging::log_error(
-            LOG_TAG,
-            "Failed to post handler success response. Http response code: %ld. %s",
-            http_response_code,
-            resp.get_body().c_str());
+            LOG_TAG, "Failed to post handler success response. Http response code: %ld.", http_response_code);
         return aws::http::response_code(http_response_code);
     }