s390/qeth: handle error due to unsupported transport mode

[ Upstream commit 2e3d7fa5d29b7ab649fdf8f9533ae0c0888a7fac ]

Along with z/VM NICs, there's additional device types that only support
a specific transport mode (eg. external-bridged IQD).
Identify the corresponding error code, and raise a fitting error message
so that the user knows to adjust their device configuration.

On top of that also fix the subsequent error path, so that the rejected
cmd doesn't need to wait for a timeout but gets cancelled straight away.

Fixes: 4a71df50 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>