raw/ioat: fix memory leak in device configure

raw/ioat: fix memory leak in device configure

During device configure, memory is allocated for "hdl_ring_flags". In the
event of another call to the device configure function (reconfigure), a
memory leak would occur. This patch fixes the memory leak by free'ing the
memory before reallocating it.

Fixes: 245efe544d8e ("raw/ioat: report status of completed jobs")
Cc: stable@dpdk.org
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>