net: sparx5: fix a couple warning messages

The WARN_ON() macro takes a condition, not a warning message.

Fixes: 0933bd04

 ("net: sparx5: Add support for ptp clocks")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220314140327.GB30883@kili


Signed-off-by: Paolo Abeni <pabeni@redhat.com>