remote: fix odd comma operator
    
    Commit 1882c0bd accidentally used ',' instead of ';'; oddly
    enough, the result was still syntactically valid (yes, C is
    a fun language).  But it made me do a double take; it's better
    to use idiomatic syntax.
    
    * daemon/remote.c (remoteRelayDomainEventDeviceAdded): Fix
    harmless typo.
    
    Signed-off-by: Eric Blake <eblake@redhat.com>