Fix Coverity null pointer dereference warning

Author: nyalldawson

tests/src/core/testqgsgeometry.cpp

@@ -4040,11 +4040,11 @@ void TestQgsGeometry::directionNeutralSegmentation()
 {
   //Tests, if segmentation of a circularstring is the same in both directions
   QString CWCircularStringWkt( QStringLiteral( "CIRCULARSTRING( 0 0, 0.5 0.5, 0.83 7.33 )" ) );
-  QgsCircularString *CWCircularString = dynamic_cast<QgsCircularString *>( QgsGeometryFactory::geomFromWkt( CWCircularStringWkt ) );
+  QgsCircularString *CWCircularString = static_cast<QgsCircularString *>( QgsGeometryFactory::geomFromWkt( CWCircularStringWkt ) );
   QgsLineString *CWLineString = CWCircularString->curveToLine();
 
   QString CCWCircularStringWkt( QStringLiteral( "CIRCULARSTRING( 0.83 7.33, 0.5 0.5, 0 0 )" ) );
-  QgsCircularString *CCWCircularString = dynamic_cast<QgsCircularString *>( QgsGeometryFactory::geomFromWkt( CCWCircularStringWkt ) );
+  QgsCircularString *CCWCircularString = static_cast<QgsCircularString *>( QgsGeometryFactory::geomFromWkt( CCWCircularStringWkt ) );
   QgsLineString *CCWLineString = CCWCircularString->curveToLine();
   QgsLineString *reversedCCWLineString = CCWLineString->reversed();