ch: Actually remove device in chDomainDetachDeviceLive()

ch: Actually remove device in chDomainDetachDeviceLive()

Inside of chDomainDetachDeviceLive() there are two variables that
are important in this case: 'match' and 'detach'. The first one
contains device definition as parsed from user provided XML, the
other contains pointer to the device definition inside
virDomainDef (as returned by chDomainFindDisk()).

Now, when chDomainRemoveDevice() is called, it looks up the
device inside virDomainDef and removes it (using pointer
comparison). Well, that means 'detach' must be passed as an
argument instead of 'match'.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>