Supply missing third arg in skey.

During the change to the new buffer api the third arg to
sshbuf_get_cstring was ommitted.  Fixes build when configured with skey.

1 files changed, 1 insertions, 1 deletions

diff --git a/monitor_wrap.c b/monitor_wrap.c
index 1409a1e55..cb1c999e0 100644
--- a/monitor_wrap.c
+++ b/monitor_wrap.c
@@ -903,7 +903,7 @@ mm_skey_query(void *ctx, char **name, char **infotxt,
         }
 
         /* Get the challenge, and format the response */
-        if ((r = sshbuf_get_cstring(m, &challenge)) != 0)
+        if ((r = sshbuf_get_cstring(m, &challenge, NULL)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
         sshbuf_free(m);