remove redundant code.

Author: zhumin8

gax-java/gax-grpc/src/main/java/com/google/api/gax/grpc/GrpcLoggingInterceptor.java

@@ -84,11 +84,7 @@ public void onMessage(RespT message) {
 
               @Override
               public void onClose(Status status, Metadata trailers) {
-                try {
-                  logResponse(status, logDataBuilder, LOGGER);
-                } finally {
-                  logDataBuilder = null; // release resource
-                }
+                logResponse(status, logDataBuilder, LOGGER);
                 super.onClose(status, trailers);
               }
             };
@@ -156,7 +152,6 @@ <RespT> void recordResponsePayload(RespT message, LogData.Builder logDataBuilder
 
   void logResponse(Status status, LogData.Builder logDataBuilder, Logger logger) {
     try {
-
       if (logger.isInfoEnabled()) {
         logDataBuilder.responseStatus(status.getCode().toString());
       }

gax-java/gax-httpjson/src/main/java/com/google/api/gax/httpjson/HttpJsonLoggingInterceptor.java

@@ -85,11 +85,7 @@ public void onMessage(RespT message) {
 
               @Override
               public void onClose(int statusCode, HttpJsonMetadata trailers) {
-                try {
-                  logResponse(statusCode, logDataBuilder, LOGGER);
-                } finally {
-                  logDataBuilder = null; // release resource
-                }
+                logResponse(statusCode, logDataBuilder, LOGGER);
                 super.onClose(statusCode, trailers);
               }
             };