virsh: use virBufferTrim in cmdDomFSInfo
virsh: use virBufferTrim in cmdDomFSInfo

Add comma after every string and trim the final one.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

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