net: ethtool: pse-pd: Fix possible null-deref

net: ethtool: pse-pd: Fix possible null-deref

Fix a possible null dereference when a PSE supports both c33 and PoDL, but
only one of the netlink attributes is specified. The c33 or PoDL PSE
capabilities are already validated in the ethnl_set_pse_validate() call.

Signed-off-by: Kory Maincent <[email protected]>
Reported-by: Jakub Kicinski <[email protected]>
Closes: https://lore.kernel.org/netdev/[email protected]/
Fixes: 4d18e3ddf427 ("net: ethtool: pse-pd: Expand pse commands with the PSE PoE interface")
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>