ptp: Fix error message on failed pin verification

On failed verification of PTP clock pin, error message prints channel
number instead of pin index after "pin", which is incorrect.

Fix error message by adding channel number to the message and printing
pin number instead of channel number.

Fixes: 6092315d

 ("ptp: introduce programmable pins.")
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20240604120555.16643-1-karol.kolacinski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>