oc: Use enum mapistore_error instead of int

This specifies a little the scope of the variable to make it
more realistic with the actual values it may have. We do have
a static typed compiled language, why don't we use it?

OpenChange/MAPIStoreFAIMessage.m

@@ -45,8 +45,8 @@
                          andType: MAPISTORE_FAI_TABLE];
 }
 
-- (int) getPidTagAssociated: (void **) data
-                   inMemCtx: (TALLOC_CTX *) memCtx
+- (enum mapistore_error) getPidTagAssociated: (void **) data
+                                    inMemCtx: (TALLOC_CTX *) memCtx
 {
   return [self getYes: data inMemCtx: memCtx];
 }