simplify

Device/Detector/SimulationAreaIterator.cpp

@@ -49,10 +49,7 @@ size_t SimulationAreaIterator::detectorIndex() const
 
 SimulationAreaIterator& SimulationAreaIterator::operator++()
 {
-    size_t index = nextIndex(m_index);
-    if (index != m_index)
-        m_index = index;
-
+    m_index = nextIndex(m_index);
     return *this;
 }