Curl_sndbufset is (at times) defined in the header, no need to do it again here

lib/connect.c

@@ -719,8 +719,6 @@ void Curl_sndbufset(curl_socket_t sockfd)
   int val = CURL_MAX_WRITE_SIZE + 32;
   setsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, (const char *)&val, sizeof(val));
 }
-#else
-#define Curl_sndbufset(y)
 #endif