net: adjust socket level ICW to cope with ipv6 variant of {recv, send}msg

After the previous patch we have ipv{6,4} variants for {recv,send}msg,
we should use the generic _INET ICW variant to call into the proper
build-in.

This also allows dropping the now unused and rather ugly _INET4 ICW macro

v1 -> v2:
 - use ICW macro to declare inet6_{recv,send}msg
 - fix a couple of checkpatch offender in the code context
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/socket.c

@@ -103,13 +103,6 @@
 #include <net/busy_poll.h>
 #include <linux/errqueue.h>
 
-/* proto_ops for ipv4 and ipv6 use the same {recv,send}msg function */
-#if IS_ENABLED(CONFIG_INET)
-#define INDIRECT_CALL_INET4(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
-#else
-#define INDIRECT_CALL_INET4(f, f1, ...) f(__VA_ARGS__)
-#endif
-
 #ifdef CONFIG_NET_RX_BUSY_POLL
 unsigned int sysctl_net_busy_read __read_mostly;
 unsigned int sysctl_net_busy_poll __read_mostly;
@@ -641,10 +634,13 @@ EXPORT_SYMBOL(__sock_tx_timestamp);
 
 INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
 					   size_t));
+INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
+					    size_t));
 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
 {
-	int ret = INDIRECT_CALL_INET4(sock->ops->sendmsg, inet_sendmsg, sock,
-				      msg, msg_data_left(msg));
+	int ret = INDIRECT_CALL_INET(sock->ops->sendmsg, inet6_sendmsg,
+				     inet_sendmsg, sock, msg,
+				     msg_data_left(msg));
 	BUG_ON(ret == -EIOCBQUEUED);
 	return ret;
 }
@@ -870,12 +866,15 @@ void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
 EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
 
 INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
-					   size_t , int ));
+					   size_t, int));
+INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
+					    size_t, int));
 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
 				     int flags)
 {
-	return INDIRECT_CALL_INET4(sock->ops->recvmsg, inet_recvmsg, sock, msg,
-				   msg_data_left(msg), flags);
+	return INDIRECT_CALL_INET(sock->ops->recvmsg, inet6_recvmsg,
+				  inet_recvmsg, sock, msg, msg_data_left(msg),
+				  flags);
 }
 
 /**