qemumonitortestutils: Don't crash on non fully initialized test
qemumonitortestutils: Don't crash on non fully initialized test

The qemumonitorjsontest crashed when one of the initialization steps
done before starting the worker thread failed. This patch fixes this by
trying to pthread_join() the thread only after it was created.

shugaoye/libvirt,fabianfreyer/libvirt,taget/libvirt,crobinso/libvirt,eskultety/libvirt,cbosdo/libvirt,libvirt/libvirt,datto/libvirt,rlaager/libvirt,andreabolognani/libvirt,zippy2/libvirt,nertpinx/libvirt,eskultety/libvirt,libvirt/libvirt,elmarco/libvirt,jardasgit/libvirt,jardasgit/libvirt,eskultety/libvirt,VenkatDatta/libvirt,zippy2/libvirt,taget/libvirt,cbosdo/libvirt,andreabolognani/libvirt,nertpinx/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,rlaager/libvirt,elmarco/libvirt,nertpinx/libvirt,taget/libvirt,jfehlig/libvirt,agx/libvirt,datto/libvirt,crobinso/libvirt,cbosdo/libvirt,eskultety/libvirt,zhlcindy/libvirt-1.1.4-maintain,VenkatDatta/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,olafhering/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,libvirt/libvirt,andreabolognani/libvirt,datto/libvirt,zippy2/libvirt,olafhering/libvirt,olafhering/libvirt,jardasgit/libvirt,datto/libvirt,agx/libvirt,taget/libvirt,rlaager/libvirt,elmarco/libvirt,jardasgit/libvirt,agx/libvirt,libvirt/libvirt,shugaoye/libvirt,agx/libvirt,olafhering/libvirt,andreabolognani/libvirt,jardasgit/libvirt,agx/libvirt,zhlcindy/libvirt-1.1.4-maintain,fabianfreyer/libvirt,nertpinx/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,rlaager/libvirt,elmarco/libvirt,cbosdo/libvirt,rlaager/libvirt,taget/libvirt,jfehlig/libvirt,zhlcindy/libvirt-1.1.4-maintain,elmarco/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,zhlcindy/libvirt-1.1.4-maintain,shugaoye/libvirt,shugaoye/libvirt,datto/libvirt,crobinso/libvirt,VenkatDatta/libvirt,eskultety/libvirt,cbosdo/libvirt,zhlcindy/libvirt-1.1.4-maintain,jfehlig/libvirt