dma/idxd: fix partial freeing in PCI close

dma/idxd: fix partial freeing in PCI close

During PCI device close, any allocated memory needs to be free'd.
Currently, one of the free's is being called on an incorrect idxd_dmadev
struct member, namely 'batch_idx_ring'.

At device creation, memory is allocated for both 'batch_comp_ring' and
'batch_idx_ring' simultaneously. Calling free only on 'batch_idx_ring'
meant the first half of this memory was not being free'd, leading to the
memleak.

This patch fixes this memleak by calling free on 'batch_comp_ring' which
will free the memory for both rings.

Fixes: 9449330a8458 ("dma/idxd: create dmadev instances on PCI probe")
Cc: stable@dpdk.org
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>