Fix a small bug in XPath evaluation code
diff --git a/xpath.c b/xpath.c
index 8482c40..b24ca69 100644
--- a/xpath.c
+++ b/xpath.c
@@ -12655,7 +12655,7 @@
             return (total);
 #ifdef XP_OPTIMIZED_FILTER_FIRST
 	case XPATH_OP_FILTER:
-                total =+ xmlXPathCompOpEvalFilterFirst(ctxt, op, first);
+                total += xmlXPathCompOpEvalFilterFirst(ctxt, op, first);
             return (total);
 #endif
         default: