Fix discard of expected errors
Fix discard of expected errors

In a couple of commands virsh catches & ignores errors, but fails
to reset last_error. Thus the error is ignored, but still reported
to the user.

* tools/virsh.c: Reset last_error if ignoring an error

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