net/mlx5: fix Rx queue count calculation

net/mlx5: fix Rx queue count calculation

There are a few discrepancies in the Rx queue count calculation.

The wrong index is used to calculate the number of used descriptors
in an Rx queue in case of the compressed CQE processing. The global
CQ index is used while we really need an internal index in a single
compressed session to get the right number of elements processed.

The total number of CQs should be used instead of the number of mbufs
to find out about the maximum number of Rx descriptors. These numbers
are not equal for the Multi-Packet Rx queue.

Allow the Rx queue count calculation for all possible Rx bursts since
CQ handling is the same for regular, vectorized, and multi-packet Rx
queues.

Fixes: 26f04883441a ("net/mlx5: support Rx queue count API")
Cc: stable@dpdk.org
Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>