[crosutils] Remove test-image-specific change of core_pattern
[crosutils] Remove test-image-specific change of core_pattern

We were snaking core dumps out from under the crash reporter on test images, and no one was even using them.  We'd like to leverage the crash reporter to detect that crashes happened during a test run, so disable this.

BUG=7936
TEST=spin up a VM, send SEGV to chrome.  crash_reporter messages should appear in /var/log/messages

Change-Id: Icc2be55616ac931ca3ec1a7810ea3e09a006a26b

Review URL: http://codereview.chromium.org/4019006

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