Merge branch 'warn.PileUpComps-20180305' into 'master'

PileUpComps: Fix compilation warning.

See merge request atlas/athena!9394

(cherry picked from commit 687158a1 [formerly 9b7efaa7])

6ab82eac PileUpComps: Fix compilation warning.

Former-commit-id: 626dfb5b

Control/PileUpComps/src/ArrayBM.cxx

@@ -60,7 +60,7 @@ StatusCode ArrayBM::initialize()
     m_signalPattern = new double[m_ipLength];
   }
   // Modification for empty bunches option
-  if (m_emptyBunches<0 || std::abs(m_emptyBunches)>m_ipLength){
+  if (m_emptyBunches<0 || std::abs(m_emptyBunches)>static_cast<int>(m_ipLength)){
     // Easy case: Just flip all the bunches
     for (size_t i=0;i<m_ipLength;++i){
       if (rProp[i]>0.) m_signalPattern[i]=0.;