devlink: use the correct handle flag for port param show

devlink: use the correct handle flag for port param show

Port param show command arg parser used the devlink dev flag
instead of the port, which caused to not identify the port device
argument, causing the following error:

$ devlink port param show eth0 name link_type
Wrong identification string format.
Devlink identification ("bus_name/dev_name") expected

Use the correct the devlink handle flag.

Fixes: 70faecdca8f5 ("devlink: implement dump selector for devlink objects show commands")
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>