Valgrind: Consistently use nullptr

Fixed by clang-tidy modernize-use-nullptr.

Change-Id: I9ae41e4d76168fa5a2e379eb1cdf605e4d106596
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/plugins/valgrind/callgrind/callgrindparser.h

@@ -50,7 +50,7 @@ class Parser : public QObject
     Q_OBJECT
 
 public:
-    explicit Parser(QObject *parent = 0);
+    explicit Parser(QObject *parent = nullptr);
     ~Parser() override;
 
     // get and take ownership of the parsing results. If this function is not called the repository

src/plugins/valgrind/callgrind/callgrindproxymodel.h

@@ -38,7 +38,7 @@ class DataProxyModel : public QSortFilterProxyModel
     Q_OBJECT
 
 public:
-    explicit DataProxyModel(QObject *parent = 0);
+    explicit DataProxyModel(QObject *parent = nullptr);
 
     void setSourceModel(QAbstractItemModel *sourceModel) override;
 

src/plugins/valgrind/callgrind/callgrindstackbrowser.h

@@ -38,7 +38,7 @@ class StackBrowser : public QObject
     Q_OBJECT
 
 public:
-    explicit StackBrowser(QObject *parent = 0);
+    explicit StackBrowser(QObject *parent = nullptr);
 
     void select(const Function *item);
     const Function *current() const;

src/plugins/valgrind/valgrindrunner.h

@@ -41,7 +41,7 @@ class ValgrindRunner : public QObject
     Q_OBJECT
 
 public:
-    explicit ValgrindRunner(QObject *parent = 0);
+    explicit ValgrindRunner(QObject *parent = nullptr);
     ~ValgrindRunner() override;
 
     void setValgrindExecutable(const QString &executable);