Fix bug uncovered by Norm Walsh.  On call to function to test
for a proximity function, pass opPos instead of op (duh).

diff --git a/src/org/apache/xpath/axes/WalkerFactory.java b/src/org/apache/xpath/axes/WalkerFactory.java
index 72224e6..f0c81d6 100644
--- a/src/org/apache/xpath/axes/WalkerFactory.java
+++ b/src/org/apache/xpath/axes/WalkerFactory.java
@@ -434,8 +434,7 @@
       case OpCodes.OP_LOCATIONPATH:
         break; // OK
       case OpCodes.OP_FUNCTION:
-        boolean isProx 
-          = functionProximateOrContainsProximate(compiler, op);
+        boolean isProx = functionProximateOrContainsProximate(compiler, opPos);
         if(isProx)
           return true;
         break;