node_device_driver.c: don't write beyond EOB for 4K-byte symlink
node_device_driver.c: don't write beyond EOB for 4K-byte symlink

* src/node_device/node_device_driver.c (update_driver_name): The
previous code would write one byte beyond the end of the 4KiB
stack buffer when presented with a symlink value of exactly that
length (very unlikely).  Remove the automatic buffer and use
virFileResolveLink in place of readlink.  Suggested by Daniel Veillard.

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