sfc: Fix some incorrect or redundant comments

In particular, the comment about EVQ_RPTR_REG is based on inconsistent
preliminary hardware documentation, though the following code was
fixed long before release.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index f63a32c..1b8d836 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -1730,7 +1730,7 @@
 
 /**************************************************************************
  *
- * Revision-dependent attributes used by efx.c
+ * Revision-dependent attributes used by efx.c and nic.c
  *
  **************************************************************************
  */