Fix metadata.getBucket callback to handle raftSessionId parameter

Update test calls to metadata.getBucket to properly handle the third
raftSessionId parameter that is returned but not needed in these tests.
This prevents the parameter from being incorrectly passed to the async
series callback chain.

Author: dvasilas

tests/unit/api/bucketDeleteLifecycle.js

@@ -47,7 +47,7 @@ describe('deleteBucketLifecycle API', () => {
         async.series([
             next => bucketPutLifecycle(authInfo, _makeRequest(true), log, next),
             next => bucketDeleteLifecycle(authInfo, _makeRequest(), log, next),
-            next => metadata.getBucket(bucketName, log, next),
+            next => metadata.getBucket(bucketName, log, (err, bucket, raftSessionId) => next(err, bucket)),
         ], (err, results) => {
             assert.equal(err, null, `Expected success, got error: ${err}`);
             const bucket = results[2];

tests/unit/api/bucketDeletePolicy.js

@@ -53,7 +53,7 @@ describe('deleteBucketPolicy API', () => {
         async.series([
             next => bucketPutPolicy(authInfo, _makeRequest(true), log, next),
             next => bucketDeletePolicy(authInfo, _makeRequest(), log, next),
-            next => metadata.getBucket(bucketName, log, next),
+            next => metadata.getBucket(bucketName, log, (err, bucket, raftSessionId) => next(err, bucket)),
         ], (err, results) => {
             assert.equal(err, null, `Expected success, got error: ${err}`);
             const bucket = results[2];