lib/vty.c: add missing format string when printing out motd message

Signed-off-by: G.Balaji <balajig81@gmail.com>
diff --git a/lib/vty.c b/lib/vty.c
index e4818eb..bd1dbac 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -250,7 +250,7 @@
 	vty_out (vty, "MOTD file not found%s", VTY_NEWLINE);
     }
   else if (host.motd)
-    vty_out (vty, host.motd);
+    vty_out (vty, "%s", host.motd);
 }
 
 /* Put out prompt and wait input from user. */