net/mlx5e: Handle RQ flush in error cases

Add a timeout to avoid an infinite loop waiting for RQ's to flush. This
occurs during AER/EEH and will also happen if the device stops posting
completions due to internal error or reset, or if moving the RQ to the
error state fails. Also cleanup posted receive resources when closing
the RQ.

Fixes: f62b8bb8

 ('net/mlx5: Extend mlx5_core to support ConnectX-4 Ethernet functionality')
Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>