RestApiServlet: Do not use HttpServletResponse#getStatus()

The version of HttpServletResponse that is used at Google doesn't have
this method. The usage of this method was introduced by change
If6fd0b543.

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I9035f2a7e874fe5341eae5a43a9d5e4cfe0dae08

java/com/google/gerrit/httpd/restapi/RestApiServlet.java

diff --git a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
index cca4f69..f30fefa7 100644
--- a/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
+++ b/java/com/google/gerrit/httpd/restapi/RestApiServlet.java
@@ -685,12 +685,11 @@
           responseBytes = 0;
           if (statusCode == SC_INTERNAL_SERVER_ERROR) {
             logger.atSevere().withCause(e).log(
-                "Error in %s %s, response already committed with status %d",
-                req.getMethod(), uriForLogging(req), res.getStatus());
+                "Error in %s %s, response already committed", req.getMethod(), uriForLogging(req));
           } else {
             logger.atWarning().log(
-                "Response for %s %s already committed with status %d, wanted to set status %d",
-                req.getMethod(), uriForLogging(req), res.getStatus(), statusCode);
+                "Response for %s %s already committed, wanted to set status %d",
+                req.getMethod(), uriForLogging(req), statusCode);
           }
         } else {
           res.reset();