Ensure the resizing items aren't null (fix Coverity defect 121862).

src/modules/partition/gui/PartitionSplitterWidget.cpp

@@ -121,7 +121,7 @@ PartitionSplitterWidget::setSplitPartition( const QString& path,
              << "\nmaxSize:" << maxSize
              << "\nprfSize:" << preferredSize;
 
-    if ( m_itemToResize || m_itemToResizeNext || !m_itemToResizePath.isEmpty() )
+    if ( m_itemToResize && m_itemToResizeNext )
     {
         cDebug() << "NOTICE: trying to split partition but partition to split is already set.";
 

src/modules/partition/gui/PartitionSplitterWidget.h

@@ -44,7 +44,7 @@ struct PartitionSplitterItem
 
     static PartitionSplitterItem null() { return { QString(), QColor(), false, 0, Normal }; }
 
-    bool isNull() const { return itemPath.isEmpty() && size == 0; }
+    bool isNull() const { return itemPath.isEmpty() && size == 0 && status == Normal; }
     operator bool() const { return !isNull(); }
 };