net: sock: make sock_tx_timestamp void

Currently, sock_tx_timestamp() always returns 0. The comment that
describes the sock_tx_timestamp() function wrongly says that it
returns an error when an invalid argument is passed (from commit
20d4947353be, ``net: socket infrastructure for SO_TIMESTAMPING'').
Make the function void, so that we can also remove all the unneeded
if conditions that check for such a _non-existant_ error case in the
output path.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/socket.c b/net/socket.c
index 88f759a..36883fe 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -600,7 +600,7 @@
 }
 EXPORT_SYMBOL(sock_release);
 
-int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags)
+void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags)
 {
 	*tx_flags = 0;
 	if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
@@ -609,7 +609,6 @@
 		*tx_flags |= SKBTX_SW_TSTAMP;
 	if (sock_flag(sk, SOCK_WIFI_STATUS))
 		*tx_flags |= SKBTX_WIFI_STATUS;
-	return 0;
 }
 EXPORT_SYMBOL(sock_tx_timestamp);