dma/idxd: fix null dereference in PCI remove

dma/idxd: fix null dereference in PCI remove

The 'info' struct was being declared as a NULL pointer. If a NULL
pointer is passed to 'rte_dma_info_get', EINVAL is returned and the
struct is not populated. This subsequently causes a segfault when
dereferencing 'info'.

This patch fixes the issue by simply declaring 'info' on the stack and
passing its address to 'rte_dma_info_get'.

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>