net/macmace: Fix and clean up log messages

Don't log the unexpanded "eth%d" format string.
Log the chip revision in the probe message (consistent with mace.c).
Drop redundant debug messages for FIFO events recorded in the
interface statistics (also consistent with mace.c).

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>