mem: fix undefined behavior in NUMA-aware mapping

mem: fix undefined behavior in NUMA-aware mapping

When NUMA-aware hugepages config option is set, we rely on
libnuma to tell the kernel to allocate hugepages on a specific
NUMA node. However, we allocate node mask before we check if
NUMA is available in the first place, which, according to
the manpage [1], causes undefined behaviour.

Fix by only using nodemask when we have NUMA available.

[1] https://linux.die.net/man/3/numa_alloc_onnode

Bugzilla ID: 20
Fixes: 1b72605d2416 ("mem: balanced allocation of hugepages")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Ilya Maximets <i.maximets@samsung.com>