Minor error formatting fixes.

Signed-off-by: Colm Donelan <colm.donelan@arm.com>
Change-Id: I17823fb8b6bbabc4da327187167ce9582ee29b32
diff --git a/delegate/src/armnn_delegate.cpp b/delegate/src/armnn_delegate.cpp
index 4e99335..b2ad160 100644
--- a/delegate/src/armnn_delegate.cpp
+++ b/delegate/src/armnn_delegate.cpp
@@ -428,7 +428,7 @@
         if (loadingStatus != armnn::Status::Success)
         {
             // Network load failed.
-            throw armnn::Exception("TfLiteArmnnDelegate: Network could not be loaded:" + errorMessage);
+            throw armnn::Exception("TfLiteArmnnDelegate: Network could not be loaded: " + errorMessage);
         }
 
         ARMNN_LOG(info) << "Load ArmnnSubgraph time: " << std::setprecision(2)