IVGCVSW-3606 Support memory import for Reference backend

Signed-off-by: Ferran Balaguer <ferran.balaguer@arm.com>
Change-Id: I94bd191f88e0911ad4e4727610e81cd7afa95512
diff --git a/src/backends/cl/ClTensorHandleFactory.cpp b/src/backends/cl/ClTensorHandleFactory.cpp
index 47e36b3..87ecdfe 100644
--- a/src/backends/cl/ClTensorHandleFactory.cpp
+++ b/src/backends/cl/ClTensorHandleFactory.cpp
@@ -68,7 +68,7 @@
     return s_Id;
 }
 
-const FactoryId ClTensorHandleFactory::GetId() const
+const FactoryId& ClTensorHandleFactory::GetId() const
 {
     return GetIdStatic();
 }