ovn-northd: Fix log message style.

It's not necessary to name the program in a log message, because log
messages already include the program name (or are in a file named after
the program).

A new-line isn't needed at the end of a log message (and by convention we
leave it out) although it is harmless.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Justin Pettit <jpettit@nicira.com>

ovn/northd/ovn-northd.c

@@ -196,7 +196,7 @@ set_bindings(struct nbd_context *ctx)
 static void
 ovnnb_db_changed(struct nbd_context *ctx)
 {
-    VLOG_DBG("ovn-northd: ovn-nb db contents have changed.\n");
+    VLOG_DBG("ovn-nb db contents have changed.");
 
     set_bindings(ctx);
 }