Silenced intel compiler warnings (reported by Kjartan Maraas, bug

* tree.c pattern.c: Silenced intel compiler warnings (reported
  by Kjartan Maraas, bug #318517).
* xmlschemas.c: The above changes in pattern.c revealed an
  inconsistency wrt IDCs: we now _only_ pop XPath states, if
  we really pushed them beforehand; this was previously not
  checked for the case when we discover an element node to be
  invalid wrt the content model.
  Fixed segfault in xmlSchemaGetEffectiveValueConstraint().
diff --git a/tree.c b/tree.c
index 3031d50..fa7785b 100644
--- a/tree.c
+++ b/tree.c
@@ -6258,7 +6258,7 @@
  */
 int
 xmlUnsetProp(xmlNodePtr node, const xmlChar *name) {
-    xmlAttrPtr prop, prev = NULL;;
+    xmlAttrPtr prop;
 
     if ((node == NULL) || (node->type != XML_ELEMENT_NODE) || (name == NULL))
 	return(-1);
@@ -6270,7 +6270,6 @@
 	    xmlFreeProp(prop);
 	    return(0);
 	}
-	prev = prop;
 	prop = prop->next;
     }
     return(-1);
@@ -6287,7 +6286,7 @@
  */
 int
 xmlUnsetNsProp(xmlNodePtr node, xmlNsPtr ns, const xmlChar *name) {
-    xmlAttrPtr prop, prev = NULL;;
+    xmlAttrPtr prop;
 
     if ((node == NULL) || (node->type != XML_ELEMENT_NODE) || (name == NULL))
 	return(-1);
@@ -6303,7 +6302,6 @@
 	    xmlFreeProp(prop);
 	    return(0);
 	}
-	prev = prop;
 	prop = prop->next;
     }
     return(-1);