vtkContour3DLinearGrid: quiet an INFO message

An INFO message is always printed with default log verbosity. This
INFO message was in a function that checks a capability, so could be
logged during the course of an entirely normal operation. This changes
it to TRACE to quiet it but still make it available at higher
verbosity levels.

Filters/Core/vtkContour3DLinearGrid.cxx

@@ -1766,14 +1766,14 @@ bool vtkContour3DLinearGrid::CanFullyProcessDataObject(
       : ug->GetPointData()->GetScalars();
     if (!array)
     {
-      vtkLog(INFO, "Scalar array is null");
+      vtkLog(TRACE, "Scalar array is null");
       return true;
     }
 
     int aType = array->GetDataType();
     if (aType != VTK_UNSIGNED_INT && aType != VTK_INT && aType != VTK_FLOAT && aType != VTK_DOUBLE)
     {
-      vtkLog(INFO, "Invalid scalar array type");
+      vtkLog(TRACE, "Invalid scalar array type");
       return false;
     }