ethtool: minor doc update

Updates: commit 793cf87d ("ethtool: Set cmd field in
         ETHTOOL_GLINKSETTINGS response to wrong nwords")
Signed-off-by: NDavid Decotigny <decot@googlers.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/ethtool.h

@@ -1648,9 +1648,9 @@ enum ethtool_reset_flags {
  *	%ETHTOOL_GLINKSETTINGS: on entry, number of words passed by user
  *	(>= 0); on return, if handshake in progress, negative if
  *	request size unsupported by kernel: absolute value indicates
- *	kernel recommended size and cmd field is 0, as well as all the
- *	other fields; otherwise (handshake completed), strictly
- *	positive to indicate size used by kernel and cmd field is
+ *	kernel expected size and all the other fields but cmd
+ *	are 0; otherwise (handshake completed), strictly positive
+ *	to indicate size used by kernel and cmd field stays
  *	%ETHTOOL_GLINKSETTINGS, all other fields populated by driver. For
  *	%ETHTOOL_SLINKSETTINGS: must be valid on entry, ie. a positive
  *	value returned previously by %ETHTOOL_GLINKSETTINGS, otherwise