examples: check asprintf return value in client_info.c
examples: check asprintf return value in client_info.c

On error, asprintf returns -1 and the contents of the string
pointer is undefined. In the rest of the libvirt code,
the virAsprintf wrapper takes care of that.

Check the return value and report a generic error, since we
purposefully avoid linking to virutil.

fabianfreyer/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,jfehlig/libvirt,eskultety/libvirt,jardasgit/libvirt,eskultety/libvirt,nertpinx/libvirt,jardasgit/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,datto/libvirt,VenkatDatta/libvirt,taget/libvirt,jardasgit/libvirt,andreabolognani/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,zippy2/libvirt,jfehlig/libvirt,VenkatDatta/libvirt,taget/libvirt,libvirt/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,olafhering/libvirt,datto/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,jardasgit/libvirt,eskultety/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,libvirt/libvirt,taget/libvirt,eskultety/libvirt,nertpinx/libvirt,crobinso/libvirt,crobinso/libvirt,datto/libvirt,jardasgit/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,eskultety/libvirt,datto/libvirt,libvirt/libvirt,andreabolognani/libvirt,crobinso/libvirt,olafhering/libvirt,fabianfreyer/libvirt,andreabolognani/libvirt,taget/libvirt,datto/libvirt,olafhering/libvirt,zippy2/libvirt,taget/libvirt,andreabolognani/libvirt,libvirt/libvirt