mlxsw: spectrum: Compare local ports instead of pointers

When dumping the FDB we can't compare the actual pointers of the ports
structs, as it's possible the struct represents a vPort instead of the
underlying physical port.

Solve this by comparing the local port number instead, as it's shared
between the physical ports and all the vPorts on top of him.

Fixes: 54a73201 ("mlxsw: spectrum: Adjust switchdev ops for VLAN devices")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>