No need for this routine to be global

Causes subtle misbehavior elsewhere

Change-Id: I3a0ade26e8e03b8c5dc8e722f6a01fb99ec7a1e0
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/src/vnet/tls/tls.c b/src/vnet/tls/tls.c
index 23ba70a..d7dcb6d 100644
--- a/src/vnet/tls/tls.c
+++ b/src/vnet/tls/tls.c
@@ -709,7 +709,7 @@
   tls_vfts[type] = *vft;
 }
 
-clib_error_t *
+static clib_error_t *
 tls_init (vlib_main_t * vm)
 {
   vlib_thread_main_t *vtm = vlib_get_thread_main ();