net: Move the comment about unsettable socket-level options to default clause and update its reference.

We implement the SO_SNDLOWAT etc not to be settable and return
ENOPROTOOPT per 1003.1g 7.  Move the comment to appropriate
position and update the reference.

Signed-off-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/sock.c

@@ -928,8 +928,6 @@ set_rcvbuf:
 			sk->sk_mark = val;
 		break;
 
-		/* We implement the SO_SNDLOWAT etc to
-		   not be settable (1003.1g 5.3) */
 	case SO_RXQ_OVFL:
 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
 		break;
@@ -1234,6 +1232,9 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 		break;
 
 	default:
+		/* We implement the SO_SNDLOWAT etc to not be settable
+		 * (1003.1g 7).
+		 */
 		return -ENOPROTOOPT;
 	}