net/mlx5: Fix command entry leak in Internal Error State

[ Upstream commit cece6f432cca9f18900463ed01b97a152a03600a ]

Processing commands by cmd_work_handler() while already in Internal
Error State will result in entry leak, since the handler process force
completion without doorbell. Forced completion doesn't release the entry
and event completion will never arrive, so entry should be released.

Fixes: 73dd3a48 ("net/mlx5: Avoid using pending command interface slots")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>