libxl: Domain destroy: unlock userdata earlier

libxl: Domain destroy: unlock userdata earlier

Unlock the userdata before we actually call xc_domain_destroy.  This
leaves open the possibility that other libxl callers will see the
half-destroyed domain (with no devices, paused), but this is fine.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Jim Fehlig <jfehlig@suse.com>
Tested-by: Jim Fehlig <jfehlig@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>