ethtool: Remove exception to the requirement of holding RTNL lock

Commit e52ac33 ('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>

include/linux/ethtool.h

@@ -896,8 +896,7 @@ static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings)
  *
  * 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.
  *