Some kernel versions expose broken NUMA topology for some machines.
This causes the LXC/UML drivers to fail to start. QEMU driver was
already fixed for this problem

* src/lxc_conf.c: Log and ignore failure to populate NUMA info
* src/uml_conf.c: Log and ignore failure to populate NUMA info
* src/capabilities.c: Reset nnumaCell to 0 after freeing