Make public headers compile with -Wzero-as-null-pointer-constant

... or equivalent.

QtBase 5.6 headers already compile that way, so let the other
modules follow suit.

Change-Id: I79c74046eaf224235cc80a4323fefd2c083b007f
Task-number: QTBUG-45291
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/charts/axis/logvalueaxis/qlogvalueaxis.h b/src/charts/axis/logvalueaxis/qlogvalueaxis.h
index 1bcff590..bd35c9f5 100644
--- a/src/charts/axis/logvalueaxis/qlogvalueaxis.h
+++ b/src/charts/axis/logvalueaxis/qlogvalueaxis.h
@@ -41,11 +41,11 @@ class QT_CHARTS_EXPORT QLogValueAxis : public QAbstractAxis
     Q_PROPERTY(qreal base READ base WRITE setBase NOTIFY baseChanged)
 
 public:
-    explicit QLogValueAxis(QObject *parent = 0);
+    explicit QLogValueAxis(QObject *parent = Q_NULLPTR);
     ~QLogValueAxis();
 
 protected:
-    QLogValueAxis(QLogValueAxisPrivate &d, QObject *parent = 0);
+    QLogValueAxis(QLogValueAxisPrivate &d, QObject *parent = Q_NULLPTR);
 
 public:
     AxisType type() const;