gendispatch: Use proper error for limit checking
gendispatch: Use proper error for limit checking

All other places use VIR_ERR_RPC except this one, let's be consistent,
shall we?

Signed-off-by: Martin Kletzander <e82f23e74d43760279ebcc505dac4ae70d5627d0@redhat.com>

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