net/mlx5: fix probing device in legacy bonding mode

net/mlx5: fix probing device in legacy bonding mode

If the device was configured as legacy bond one (without
involving E-Switch), the mlx5 PMD erroneously tried to deduce
the vport index raising the fatal error and preventing
device from being used.

The patch checks whether there is E-Switch present and we
should use vport index indeed.

Fixes: 2eb4d0107acc ("net/mlx5: refactor PCI probing on Linux")
Fixes: d5c06b1b10ae ("net/mlx5: query vport index match mode and parameters")
Cc: stable@dpdk.org
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>