libxl: Resolve Coverity NULL_RETURNS
libxl: Resolve Coverity NULL_RETURNS

With all the changes in my previous foray into this code, I forgot to
remove the libxlDomainEventQueue(driver, event); call inside the
dom == NULL condition.

Signed-off-by: John Ferlan <87558058f6f829e5ec976c8ef960720af4ff9c7d@redhat.com>

crobinso/libvirt,VenkatDatta/libvirt,taget/libvirt,jfehlig/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,elmarco/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,rlaager/libvirt,datto/libvirt,jfehlig/libvirt,elmarco/libvirt,andreabolognani/libvirt,datto/libvirt,rlaager/libvirt,nertpinx/libvirt,andreabolognani/libvirt,elmarco/libvirt,jardasgit/libvirt,olafhering/libvirt,elmarco/libvirt,crobinso/libvirt,zippy2/libvirt,shugaoye/libvirt,agx/libvirt,jardasgit/libvirt,nertpinx/libvirt,agx/libvirt,agx/libvirt,olafhering/libvirt,eskultety/libvirt,shugaoye/libvirt,datto/libvirt,eskultety/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,taget/libvirt,nertpinx/libvirt,shugaoye/libvirt,elmarco/libvirt,shugaoye/libvirt,VenkatDatta/libvirt,zippy2/libvirt,jfehlig/libvirt,eskultety/libvirt,datto/libvirt,libvirt/libvirt,eskultety/libvirt,fabianfreyer/libvirt,libvirt/libvirt,crobinso/libvirt,rlaager/libvirt,andreabolognani/libvirt,agx/libvirt,rlaager/libvirt,jardasgit/libvirt,taget/libvirt,datto/libvirt,zippy2/libvirt,nertpinx/libvirt,taget/libvirt,crobinso/libvirt,libvirt/libvirt,libvirt/libvirt,taget/libvirt,jardasgit/libvirt,andreabolognani/libvirt,nertpinx/libvirt,zippy2/libvirt,olafhering/libvirt,rlaager/libvirt,shugaoye/libvirt,agx/libvirt,olafhering/libvirt,eskultety/libvirt