io: fix maybe-uninitialized warning in test (-O2)

/home/rusty/devel/cvs/ccan/ccan/io/test/run-01-start-finish.c: In function ‘main’:
/home/rusty/devel/cvs/ccan/ccan/io/test/run-01-start-finish.c:89:7: warning: ‘addrinfo’ may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (connect(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) != 0)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan/io/io.h

@@ -47,7 +47,8 @@ struct io_conn;
  *	int fd[2];
  *	struct io_conn *conn;
  *
- *	pipe(fd);
+ *	if (pipe(fd) != 0)
+ *		exit(1);
  *	conn = io_new_conn(NULL, fd[0], conn_init, (const char *)"hi!");
  *	if (!conn)
  *		exit(1);

ccan/io/test/run-01-start-finish.c

@@ -69,7 +69,7 @@ static int make_listen_fd(const char *port, struct addrinfo **info)
 int main(void)
 {
 	int state = 0;
-	struct addrinfo *addrinfo;
+	struct addrinfo *addrinfo = NULL;
 	struct io_listener *l;
 	int fd;
 

ccan/io/test/run-02-read.c

@@ -71,7 +71,7 @@ static int make_listen_fd(const char *port, struct addrinfo **info)
 int main(void)
 {
 	struct data *d = malloc(sizeof(*d));
-	struct addrinfo *addrinfo;
+	struct addrinfo *addrinfo = NULL;
 	struct io_listener *l;
 	int fd, status;
 

ccan/time/test/run-check.c

@@ -156,7 +156,8 @@ int main(void)
 	ok1(t3.ts.tv_sec == 2);
 	ok1(t3.ts.tv_nsec == 147483648);
 
-	pipe(fds);
+	if (pipe(fds) != 0)
+		exit(1);
 
 	fflush(stdout);
 	switch (fork()) {