Fixed an error in a call to the error function.

Cython/Compiler/Symtab.py

@@ -195,7 +195,7 @@ class Scope:
         # declared.
         dict = self.entries
         if name and dict.has_key(name):
-            warning(pos, "'%s' redeclared (ignoring second declaration)" % name, 0)
+            error(pos, "'%s' redeclared (ignoring second declaration)" % name)
         entry = Entry(name, cname, type, pos = pos)
         entry.in_cinclude = self.in_cinclude
         if name: