ProcFS: minor fixes to overflow handling

dcdbpusher/sensors/procfs/ProcfsParser.cpp

@@ -629,7 +629,7 @@ bool SARParser::_readMetrics() {
 					if (_latestBuffer >= _columnRawReadings[(lineCtr - 1) * DEFAULTMETRICS + colCtr])
 						_latestValue = _latestBuffer - _columnRawReadings[(lineCtr - 1) * DEFAULTMETRICS + colCtr];
 					else
-						return false;
+						_latestValue = _latestBuffer + (ULLONG_MAX - _columnRawReadings[(lineCtr - 1) * DEFAULTMETRICS + colCtr]);
 					_columnRawReadings[(lineCtr - 1) * DEFAULTMETRICS + colCtr] = _latestBuffer;
 					_accumulators[accIdx] += _latestValue;
 					// Second part of the if: if the line contains node-level CPU metrics (starts with "cpu") and the