update splunk emitter error attrs (#35)

Author: keith-decker

util/opentelemetry-util-genai-emitters-splunk/src/opentelemetry/util/genai/emitters/splunk.py

@@ -479,13 +479,9 @@ def _emit_event(
             if response_identifier:
                 ev["gen_ai.response.id"] = response_identifier
             if result.error is not None:
-                ev["gen_ai.evaluation.error.type"] = (
-                    result.error.type.__qualname__
-                )
+                ev["error.type"] = result.error.type.__qualname__
                 if getattr(result.error, "message", None):
-                    ev["gen_ai.evaluation.error.message"] = (
-                        result.error.message
-                    )
+                    ev["error.message"] = result.error.message
             if ev:
                 evaluations.append(ev)