qemuDomainAttachSCSIVHostDevice: manage /dev entry
qemuDomainAttachSCSIVHostDevice: manage /dev entry

Again, one missed bit. This time without this commit there is no
/dev entry in the namespace of the qemu process when attaching
vhost SCSI device.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

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