net/mlx5: fix overwriting bit-fields in SW Rx queue

net/mlx5: fix overwriting bit-fields in SW Rx queue

Bit-fields in mlx5_rxq_data can be changed on the fly by a control plane -
e.g. rxq->mark. However, vectorized Rx uses a bit-field to mark pending
errors. Even if one bit is written, consequence is to write the whole
integer and this can cause a synchronization issue - two entities write to
a same block without locking. As the pending_err bit is entirely internal
use for the datapath, this can be replaced with a local variable.

Fixes: 6cb559d67b83 ("net/mlx5: add vectorized Rx/Tx burst for x86")
Fixes: 570acdb1da8a ("net/mlx5: add vectorized Rx/Tx burst for ARM")
Cc: stable@dpdk.org
Signed-off-by: Yongseok Koh <yskoh@mellanox.com>