Merge branch 'clang.TrigEFMissingET-20180705' into 'master'

TrigEFMissingET: Fix clang warning.

See merge request atlas/athena!12554

Trigger/TrigAlgorithms/TrigEFMissingET/src/EFMissingETFromCellsMT.h

@@ -31,7 +31,7 @@ class EFMissingETFromCellsMT: public extends<AthAlgTool, IMissingETTool> {
 
   virtual ~EFMissingETFromCellsMT(){}
 
-  virtual StatusCode  initialize();
+  virtual StatusCode  initialize() override;
 
   virtual StatusCode update( xAOD::TrigMissingET *met,
 			     TrigEFMissingEtHelper *metHelper ) const override;