Resolve implicit conversion from nullptr to false

    Geometry/EcalAlgo/src/EcalBarrelGeometry.cc:27:21: error: implicit
    conversion of nullptr constant to 'bool' [-Werror,-Wnull-conversion]
       m_check        ( nullptr ),
       ~~~~~~~          ^~~~~~~
                        false

    Geometry/EcalAlgo/src/EcalEndcapGeometry.cc:25:14: error: implicit
    conversion of nullptr constant to 'bool' [-Werror,-Wnull-conversion]
        m_check( nullptr ),
        ~~~~~~~  ^~~~~~~
                 false

Signed-off-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>