malloc: fix allocation with unknown socket ID

malloc: fix allocation with unknown socket ID

When using rte_malloc() from a thread which is not bound to a numa
socket (the typical case is a control thread, but it can also happen
on a dataplane thread if its cpu affinity is on cores attached to
several sockets), the used heap is the one from numa socket 0, which
may not have available memory.

Fix this by selecting the first socket which has available memory.

Note: malloc_get_numa_socket() is only used from one .c file, so move
it there, and remove the inline keyword.

Fixes: b94580d6887e ("malloc: avoid unknown socket id")
Cc: stable@dpdk.org
Signed-off-by: Ilyes Ben Hamouda <ilyes.ben_hamouda@6wind.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: David Marchand <david.marchand@redhat.com>