Update README

Change-Id: I18e612cac47e44ccae95d74a0bf0bf675ef1ee0a
diff --git a/trellis/README.md b/trellis/README.md
index 9929757..595f97e 100644
--- a/trellis/README.md
+++ b/trellis/README.md
@@ -45,6 +45,7 @@
 make
 sudo make install
 cd ..
+sudo ldconfig
 ```
 
 ## ONOS - Installation