qemu: Check driver is initialized up front, to avoid segfault.
qemu: Check driver is initialized up front, to avoid segfault.

If the qemu_driver was not initialized (possibly due to an error on driver
startup), we can segfault if attempting to connect to the URI.

zhlcindy/libvirt-1.1.4-maintain,emaste/libvirt,novel/fbsd-libvirt,dumbbell/libvirt,andreabolognani/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,rmarwaha/libvirt1,soulxu/libvirt-xuhj,elmarco/libvirt,zippy2/libvirt,eskultety/libvirt,datto/libvirt,dumbbell/libvirt,iam-TJ/libvirt,rmarwaha/libvirt1,wiedi/libvirt,rmarwaha/libvirt1,elmarco/libvirt,taget/libvirt,soulxu/libvirt-xuhj,iam-TJ/libvirt,jardasgit/libvirt,emaste/libvirt,agx/libvirt,datto/libvirt,usc-isi/libvirt,bjzhang/libvirt,siboulet/libvirt-openvz,crobinso/libvirt,rlaager/libvirt,siboulet/libvirt-openvz,sshah-solarflare/Libvirt-PCI-passthrough-,shugaoye/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,iam-TJ/libvirt,usc-isi/libvirt,agx/libvirt,amery/libvirt-vserver,crobinso/libvirt,cbosdo/libvirt,eskultety/libvirt,shugaoye/libvirt,libvirt/libvirt,eskultety/libvirt,jardasgit/libvirt,taget/libvirt,trainstack/libvirt,leilihh/libvirt,novel/fbsd-libvirt,warewolf/libvirt,cbosdo/libvirt,siboulet/libvirt-openvz,warewolf/libvirt,rmarwaha/libvirt,zippy2/libvirt,rbu/libvirt,kantai/libvirt-vfork,sshah-solarflare/Libvirt-PCI-passthrough-,cbosdo/libvirt,jeckersb/libvirt,wiedi/libvirt,jfehlig/libvirt,eskultety/libvirt,iam-TJ/libvirt,rlaager/libvirt,dumbbell/libvirt,datto/libvirt,dumbbell/libvirt,jardasgit/libvirt,zhlcindy/libvirt-1.1.4-maintain,warewolf/libvirt,elmarco/libvirt,trainstack/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,rlaager/libvirt,jeckersb/libvirt,novel/fbsd-libvirt,shugaoye/libvirt,kantai/libvirt-vfork,VenkatDatta/libvirt,nertpinx/libvirt,jeckersb/libvirt,novel/fbsd-libvirt,andreabolognani/libvirt,agx/libvirt,usc-isi/libvirt,warewolf/libvirt,warewolf/libvirt,libvirt/libvirt,agx/libvirt,zippy2/libvirt,agx/libvirt,datto/libvirt,fabianfreyer/libvirt,elmarco/libvirt,zhlcindy/libvirt-1.1.4-maintain,rmarwaha/libvirt,bjzhang/libvirt,soulxu/libvirt-xuhj,jeckersb/libvirt,sshah-solarflare/Libvirt-PCI-passthrough-,jfehlig/libvirt,rmarwaha/libvirt1,wiedi/libvirt,emaste/libvirt,amery/libvirt-vserver,rmarwaha/libvirt1,siboulet/libvirt-openvz,rmarwaha/libvirt,datto/libvirt,andreabolognani/libvirt,trainstack/libvirt,trainstack/libvirt,leilihh/libvirt,rmarwaha/libvirt,bjzhang/libvirt,foomango/libvirt,leilihh/libvirt,siboulet/libvirt-openvz,danwent/libvirt-ovs,danwent/libvirt-ovs,jeckersb/libvirt,kantai/libvirt-vfork,danwent/libvirt-ovs,rbu/libvirt,rmarwaha/libvirt1,novel/fbsd-libvirt,danwent/libvirt-ovs,foomango/libvirt,rbu/libvirt,nertpinx/libvirt,trainstack/libvirt,emaste/libvirt,novel/fbsd-libvirt,novel/fbsd-libvirt,novel/fbsd-libvirt,cbosdo/libvirt,taget/libvirt,libvirt/libvirt,libvirt/libvirt,emaste/libvirt,jardasgit/libvirt,rbu/libvirt,cbosdo/libvirt,jardasgit/libvirt,amery/libvirt-vserver,wiedi/libvirt,iam-TJ/libvirt,nertpinx/libvirt,jeckersb/libvirt,wiedi/libvirt,usc-isi/libvirt,zhlcindy/libvirt-1.1.4-maintain,kantai/libvirt-vfork,VenkatDatta/libvirt,leilihh/libvirt,leilihh/libvirt,dumbbell/libvirt,andreabolognani/libvirt,nertpinx/libvirt,bjzhang/libvirt,trainstack/libvirt,danwent/libvirt-ovs,taget/libvirt,wiedi/libvirt,olafhering/libvirt,rlaager/libvirt,trainstack/libvirt,andreabolognani/libvirt,usc-isi/libvirt,VenkatDatta/libvirt,taget/libvirt,novel/fbsd-libvirt,iam-TJ/libvirt,rbu/libvirt,fabianfreyer/libvirt,leilihh/libvirt,olafhering/libvirt,warewolf/libvirt,fabianfreyer/libvirt,rlaager/libvirt,soulxu/libvirt-xuhj,jfehlig/libvirt,kantai/libvirt-vfork,jeckersb/libvirt,fabianfreyer/libvirt,foomango/libvirt,eskultety/libvirt,rmarwaha/libvirt,wiedi/libvirt,iam-TJ/libvirt,amery/libvirt-vserver,shugaoye/libvirt,dumbbell/libvirt,emaste/libvirt,elmarco/libvirt,jfehlig/libvirt,rmarwaha/libvirt,olafhering/libvirt,zhlcindy/libvirt-1.1.4-maintain,crobinso/libvirt,amery/libvirt-vserver,foomango/libvirt,olafhering/libvirt,VenkatDatta/libvirt,crobinso/libvirt,zippy2/libvirt,soulxu/libvirt-xuhj,foomango/libvirt,emaste/libvirt,bjzhang/libvirt,warewolf/libvirt,shugaoye/libvirt,fabianfreyer/libvirt