staging: unisys: remove bogus error checking

The netdev we're testing for can't be removed, because its never
unregistered, so don't bother checking for it

Signed-off-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>