Fix boundary for test introduced in 3e3f1029c9ec6c63e430ff51063a6301d4b2262

This fixes breakage of  DHCPv6 relay.
diff --git a/src/rfc3315.c b/src/rfc3315.c
index c3c1c95..21fcd9b 100644
--- a/src/rfc3315.c
+++ b/src/rfc3315.c
@@ -216,9 +216,9 @@
   
   for (opt = opts; opt; opt = opt6_next(opt, end))
     {
-      if (opt6_ptr(opt, 0) + opt6_len(opt) >= end) {
+      if (opt6_ptr(opt, 0) + opt6_len(opt) > end) 
         return 0;
-      }
+     
       int o = new_opt6(opt6_type(opt));
       if (opt6_type(opt) == OPTION6_RELAY_MSG)
 	{