Fix crash in tdehwlib if /sys/devices/system/cpu/cpu* is not accessible

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit 051acc7df5)

tdecore/tdehw/tdehardwaredevices.cpp

@@ -862,9 +862,11 @@ void TDEHardwareDevices::processModifiedCPUs() {
 	if (modified) {
 		for (processorNumber=0; processorNumber<processorCount; processorNumber++) {
 			TDEGenericDevice* hwdevice = findCPUBySystemPath(TQString("/sys/devices/system/cpu/cpu%1").arg(processorNumber));
-			// Signal new information available
-			emit hardwareUpdated(hwdevice);
-			emit hardwareEvent(TDEHardwareEvent::HardwareUpdated, hwdevice->uniqueID());
+			if (hwdevice) {
+				// Signal new information available
+				emit hardwareUpdated(hwdevice);
+				emit hardwareEvent(TDEHardwareEvent::HardwareUpdated, hwdevice->uniqueID());
+			}
 		}
 	}