https://bugzilla.redhat.com/show_bug.cgi?id=1534418
Just like ec982f6d92 denies hugepages for non-existent
guest NUMA nodes in case there are some nodes configured.
Unfortunately, when there are none, qemuBuildNumaArgStr() is not
called and thus we have to have check in qemuBuildMemPathStr()
too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>