Fix possible crash in handling IO Error event
Fix possible crash in handling IO Error event

If the IO error event does not include a reason, then there
is a possible crash dispatching the event

* src/conf/domain_event.c: Missing check for a NULL reason before
  strduping allows for a crash

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