Simplify QStringList->QString conversion.

src/core/device.h

@@ -124,4 +124,3 @@ protected:
 };
 
 #endif
-

src/core/operationrunner.h

@@ -93,4 +93,3 @@ private:
 };
 
 #endif
-

src/core/partition.h

@@ -289,4 +289,3 @@ private:
 QTextStream& operator<<(QTextStream& stream, const Partition& p);
 
 #endif
-

src/core/volumemanagerdevice.cpp

@@ -32,14 +32,5 @@ VolumeManagerDevice::VolumeManagerDevice(const QString& name,
 
 QString VolumeManagerDevice::prettyDeviceNodeList() const
 {
-    QString rval;
-    for (const auto &devNode : deviceNodes()) {
-        rval += devNode + QStringLiteral(",");
-    }
-
-    if (rval.size()) {
-        //chop off the trailing colon
-        rval.chop(1);
-    }
-    return rval;
+    return deviceNodes().join(QStringLiteral(", "));
 }