Fixed a coding error that a test waited on a wrong task status update.
Fixed a coding error that a test waited on a wrong task status update.

Review: https://reviews.apache.org/r/69236

reneploetz/mesos,Gilbert88/mesos,jpeach/mesos,gsantovena/mesos,abudnik/mesos,kaysoky/mesos,dforsyth/mesos,chhsia0/mesos,reneploetz/mesos,jpeach/mesos,Gilbert88/mesos,abudnik/mesos,Gilbert88/mesos,reneploetz/mesos,chhsia0/mesos,reneploetz/mesos,Gilbert88/mesos,gsantovena/mesos,kaysoky/mesos,abudnik/mesos,gsantovena/mesos,Gilbert88/mesos,jpeach/mesos,dforsyth/mesos,reneploetz/mesos,jpeach/mesos,jpeach/mesos,chhsia0/mesos,kaysoky/mesos,dforsyth/mesos,dforsyth/mesos,jpeach/mesos,kaysoky/mesos,Gilbert88/mesos,kaysoky/mesos,gsantovena/mesos,gsantovena/mesos,chhsia0/mesos,chhsia0/mesos,reneploetz/mesos,gsantovena/mesos,kaysoky/mesos,chhsia0/mesos,reneploetz/mesos,abudnik/mesos,dforsyth/mesos,chhsia0/mesos,dforsyth/mesos,abudnik/mesos,gsantovena/mesos,kaysoky/mesos,abudnik/mesos,dforsyth/mesos,Gilbert88/mesos,jpeach/mesos,abudnik/mesos