virtiofsd: replace pipe() with g_unix_open_pipe(CLOEXEC)

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

tools/virtiofsd/helper.c

@@ -275,7 +275,7 @@ int fuse_daemonize(int foreground)
         int waiter[2];
         char completed;
 
-        if (pipe(waiter)) {
+        if (!g_unix_open_pipe(waiter, FD_CLOEXEC, NULL)) {
             fuse_log(FUSE_LOG_ERR, "fuse_daemonize: pipe: %s\n",
                      strerror(errno));
             return -1;