char: do not double-close fd when failing to add client

The caller is already closing the fd on failure.

Fixes: c3054a6e6a ("char: Factor out qmp_add_client() parts and move to chardev/")
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230306122751.2355515-3-marcandre.lureau@redhat.com>

chardev/char.c

@@ -1175,12 +1175,10 @@ bool qmp_add_client_char(int fd, bool has_skipauth, bool skipauth,
 
     if (!s) {
         error_setg(errp, "protocol '%s' is invalid", protocol);
-        close(fd);
         return false;
     }
     if (qemu_chr_add_client(s, fd) < 0) {
         error_setg(errp, "failed to add client");
-        close(fd);
         return false;
     }
     return true;