net/mlx5e: kTLS, Fix missing error unwind on unsupported cipher type

Do proper error unwinding when adding an unsupported TX/RX cipher type.
Move the switch case prior to key creation so there's less to unwind,
and change the goto label name to describe the action performed instead
of what failed.

Fixes: 4960c414 ("net/mlx5e: Support 256 bit keys with kTLS device offload")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>