qemu: Use @tmpChr in qemuDomainDetachChrDevice to build device string
qemu: Use @tmpChr in qemuDomainDetachChrDevice to build device string

So far we are passing @chr to qemuBuildChrDeviceStr. This is
suboptimal (in fact wrong) because @chr is just parsed XML
definition provided by user which by definition may lack some
information. On the other hand, @tmpChr is the one that was found
using @chr in domain definition so it contains the same amount of
information or more.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

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