Simplify status implementation

Author: Mikep86

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/InferenceException.java

@@ -20,12 +20,6 @@ public InferenceException(String message, Throwable cause, Object... args) {
     public RestStatus status() {
         // Override status so that we get the status of the cause while retaining the message of the inference exception when emitting to
         // XContent
-        RestStatus status = RestStatus.INTERNAL_SERVER_ERROR;
-        Throwable cause = getCause();
-        if (cause != null) {
-            status = ExceptionsHelper.status(cause);
-        }
-
-        return status;
+        return ExceptionsHelper.status(getCause());
     }
 }

x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/InferenceExceptionTests.java

@@ -36,4 +36,16 @@ public void testWrapException() throws Exception {
         );
         assertThat(testException.status(), equalTo(RestStatus.BAD_REQUEST));
     }
+
+    public void testNullCause() throws Exception {
+        InferenceException testException = new InferenceException("test exception", null);
+
+        XContentBuilder builder = XContentFactory.jsonBuilder();
+        builder.startObject();
+        testException.toXContent(builder, ToXContent.EMPTY_PARAMS);
+        builder.endObject();
+
+        assertThat(Strings.toString(builder), equalTo("{\"type\":\"inference_exception\",\"reason\":\"test exception\"}"));
+        assertThat(testException.status(), equalTo(RestStatus.INTERNAL_SERVER_ERROR));
+    }
 }