sfc: fix debug message format string in efx_farch_handle_rx_not_ok

Defalconisation removed one of the string arguments, but missed the
 corresponding %s.

Fixes: 5a6681e2 ("sfc: separate out SFC4000 ("Falcon") support into new sfc-falcon driver")

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>