Fixing NACL_DEBUG=1 for nacl-spawn.

ports/nacl-spawn/nacl_spawn.cc

Index: ports/nacl-spawn/nacl_spawn.cc
diff --git a/ports/nacl-spawn/nacl_spawn.cc b/ports/nacl-spawn/nacl_spawn.cc
index 0ac0e5376e25ca19063e2d79cf68015b9fd4a6b9..d727fae204495f6db2130e4b07b54754d91ec1fd 100644
--- a/ports/nacl-spawn/nacl_spawn.cc
+++ b/ports/nacl-spawn/nacl_spawn.cc
@@ -238,7 +238,7 @@ static bool GetBool(struct PP_Var dict_var, const char* key) {
   if (!VarDictionaryHasKey(dict_var, key, &value_var)) {
     return -1;
   }
-  assert(value_var.type == PP_BOOL);
+  assert(value_var.type == PP_VARTYPE_BOOL);
   bool value = value_var.value.as_bool;
   return value;
 }