Fixed RelationshipKeyPairingVisitor - all many-to-one relations with two ends will use the same (single) foreign column name at children table.

Before that fix such relations were mapped this way: "one" side used childtype.Name+"_id", "many" side used referenceToParentProperty.Name+"_id".
It seemed to work just because usually referenceToParent property name is equal to parent's type name.

Author: owerkop

src/FluentNHibernate/Visitors/RelationshipKeyPairingVisitor.cs

@@ -14,12 +14,8 @@ public override void ProcessManyToOne(ManyToOneMapping thisSide)
             // other side is always going to be a collection for a many-to-one mapping
             var otherSide = (CollectionMapping)thisSide.OtherSide;
 
-            if (thisSide.ContainingEntityType == otherSide.ContainingEntityType)
-            {
-                // special case for self-referential relationships
-                otherSide.Key.MakeColumnsEmpty(Layer.Defaults);
-                thisSide.Columns.Each(x => otherSide.Key.AddColumn(Layer.Defaults, x.Clone()));
-            }
+            otherSide.Key.MakeColumnsEmpty(Layer.Defaults);
+            thisSide.Columns.Each(x => otherSide.Key.AddColumn(Layer.Defaults, x.Clone()));
         }
     }
 }