Fix flaky RaftConsensusITest.TestFailedTransaction
Fix flaky RaftConsensusITest.TestFailedTransaction

This test failed 8/1000 runs without this fix, due to a leader
election happening which replaced the original leader determined
by the test. This caused it to fail with an unexpected "Aborted"
error.

With the fix, I looped 1000 runs with no failures.

Change-Id: Ib12126bc1ee82d8488073a3adc58ca7a5c2fd434
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/6720
Tested-by: jenkins
Reviewed-by: Michael Percy <e07a1fd797b473a9c849e618aa2ce06d8055760b@cloudera.com>

andrwng/kudu,InspurUSA/kudu,andrwng/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,andrwng/kudu,cloudera/kudu,EvilMcJerkface/kudu,helifu/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu,cloudera/kudu,helifu/kudu,InspurUSA/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,andrwng/kudu,cloudera/kudu,InspurUSA/kudu,InspurUSA/kudu,helifu/kudu,andrwng/kudu,cloudera/kudu,EvilMcJerkface/kudu,helifu/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,helifu/kudu,EvilMcJerkface/kudu,andrwng/kudu,cloudera/kudu,helifu/kudu,helifu/kudu,cloudera/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,andrwng/kudu