QStorageInfoPrivate/Linux: de-duplicate some code

Change-Id: Ie0fe0c80a61c123c12242f24830ca622a726d7ac
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/io/qstorageinfo_linux.cpp

@@ -229,11 +229,9 @@ quint64 QStorageInfoPrivate::initRootPath()
     for (auto it = infos.rbegin(); it != infos.rend(); ++it) {
         if (rootPathDevId != it->stDev || !isParentOf(it->mountPoint, oldRootPath))
             continue;
-        rootPath = std::move(it->mountPoint);
+        auto stDev = it->stDev;
-        device = std::move(it->device);
+        setFromMountInfo(std::move(*it));
-        fileSystemType = std::move(it->fsType);
+        return stDev;
-        subvolume = std::move(it->fsRoot);
-        return it->stDev;
     }
     return 0;
 }

src/corelib/io/qstorageinfo_p.h

@@ -67,13 +67,20 @@ public:
         QByteArray fsRoot;
         dev_t stDev = 0;
     };
-    QStorageInfoPrivate(MountInfo &&info)
+
-        : rootPath(std::move(info.mountPoint)),
+    void setFromMountInfo(MountInfo &&info)
-          device(std::move(info.device)),
-          subvolume(std::move(info.fsRoot)),
-          fileSystemType(std::move(info.fsType))
     {
+        rootPath = std::move(info.mountPoint);
+        fileSystemType = std::move(info.fsType);
+        device = std::move(info.device);
+        subvolume = std::move(info.fsRoot);
     }
+
+    QStorageInfoPrivate(MountInfo &&info)
+    {
+        setFromMountInfo(std::move(info));
+    }
+
 #elif defined(Q_OS_UNIX)
     void initRootPath();
     void retrieveVolumeInfo();