ethtool: Remove exception to the requirement of holding RTNL lock

Commit e52ac3398c3d772d372b9b62ab408fd5eec96840 ('net: Use device
model to get driver name in skb_gso_segment()') removed the only
in-tree caller of ethtool ops that doesn't hold the RTNL lock.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index e1d9e0e..f5647b5 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -896,8 +896,7 @@
  *
  * All operations are optional (i.e. the function pointer may be set
  * to %NULL) and callers must take this into account.  Callers must
- * hold the RTNL, except that for @get_drvinfo the caller may or may
- * not hold the RTNL.
+ * hold the RTNL lock.
  *
  * See the structures used by these operations for further documentation.
  *