[HF] Fix warning about assignment operator.

rootbench used the implicit Channel::operator=. This triggers a warning
because there is a user-declared copy constructor. By defaulting the
two, this can be avoided.

Author: hageboeck

roofit/histfactory/inc/RooStats/HistFactory/Channel.h

@@ -34,7 +34,8 @@ class Channel  {
   friend class Measurement;
 
   Channel();
-  Channel(const Channel& other);
+  Channel(const Channel& other) = default;
+  Channel & operator=(const Channel& other) = default;
   Channel(std::string Name, std::string InputFile="");
 
   /// set name of channel

roofit/histfactory/src/Channel.cxx

@@ -38,17 +38,6 @@ RooStats::HistFactory::Channel::Channel() :
   // standard constructor
 }
 
-RooStats::HistFactory::Channel::Channel(const Channel& other) :
-  fName( other.fName ),
-  fInputFile( other.fInputFile ),
-  fHistoPath( other.fHistoPath ),
-  fData( other.fData ),
-  fAdditionalData( other.fAdditionalData ),
-  fStatErrorConfig( other.fStatErrorConfig ),
-  fSamples( other.fSamples )
-{ ; }
-
-
 RooStats::HistFactory::Channel::Channel(std::string ChanName, std::string ChanInputFile) :
   fName( ChanName ), fInputFile( ChanInputFile )
 {