net/failsafe: fix removed device handling

net/failsafe: fix removed device handling

There is time between the physical removal of the device until
sub-device PMDs get a RMV interrupt. At this time DPDK PMDs and
applications still don't know about the removal and may call sub-device
control operation which should return an error.

In previous code this error is reported to the application contrary to
fail-safe principle that the app should not be aware of device removal.

Add an removal check in each relevant control command error flow and
prevent an error report to application when the sub-device is removed.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Acked-by: Gaetan Rivet <gaetan.rivet@6wind.com>