IMPALA-5349: flaky NoDirsAllocationError test
IMPALA-5349: flaky NoDirsAllocationError test

The assertion was incorrect and racy - it is ok if the write error wins
the race with the Unpin() calls, causing them to fail.

Change-Id: I023193b9ad6c6ac0ee114ad77ddf04d7d7185809
Reviewed-on: http://gerrit.cloudera.org:8080/6953
Reviewed-by: Henry Robinson <3eca10f30041813f045165784e24b5a950a6cc7e@cloudera.com>
Reviewed-by: Dan Hecht <20ebd99959f0f6e5dcb0fc319b4d8ef53a16b5fb@cloudera.com>
Tested-by: Impala Public Jenkins

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala