Wait for child to exit after killing it.
Wait for child to exit after killing it.

Use general purpose wait in case your connecting to a vm
that you didn't start.

Change-Id: Ie67e2d3235882d372d04e4a44d0781ddfc8d4645

BUG=chromium-os:10121
TEST=Ran it, caused some crashes.  Still ran test after retries.

Review URL: http://codereview.chromium.org/5757001

gtank/scripts,gtank/scripts,smilart/scripts,trnubo/scripts,vmware/coreos-scripts,zhang0137/scripts,fivethreeo/scripts,mjg59/scripts,trnubo/scripts,coreos/scripts,mischief/scripts,mischief/scripts,endocode/scripts,sigma/coreos-scripts,glevand/coreos--scripts,smilart/scripts,mischief/scripts,zhang0137/scripts,crawford/scripts,trnubo/scripts,nicescale/scripts,crawford/scripts,marineam/coreos-scripts,marineam/coreos-scripts,coreos/scripts,nicescale/scripts,bcwaldon/coreos-scripts,vmware/coreos-scripts,BugRoger/scripts,sigma/coreos-scripts,bcwaldon/coreos-scripts,sigma/coreos-scripts,endocode/scripts,BugRoger/scripts,glevand/coreos--scripts,mjg59/scripts,marineam/coreos-scripts,fivethreeo/scripts,gtank/scripts,mjg59/scripts,nicescale/scripts,smilart/scripts,crawford/scripts,vmware/coreos-scripts,andrejro/coreos--scripts,fivethreeo/scripts,endocode/scripts,bcwaldon/coreos-scripts,zhang0137/scripts,andrejro/coreos--scripts,BugRoger/scripts,andrejro/coreos--scripts