test_diffusion reference solution: corrected name of solution component

git-svn-id: svn://svn.iws.uni-stuttgart.de/DUMUX/dumux/trunk@11488 2fb0f335-1f38-0410-981e-8018bf24f1b0

test/references/diffusion-reference.vtu

@@ -2,8 +2,8 @@
 <VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian">
   <UnstructuredGrid>
     <Piece NumberOfCells="64" NumberOfPoints="81">
-      <CellData Scalars="global pressure">
-        <DataArray type="Float32" Name="global pressure" NumberOfComponents="1" format="ascii">
+      <CellData Scalars="wetting potential">
+        <DataArray type="Float32" Name="wetting potential" NumberOfComponents="1" format="ascii">
           0.097758 0.12059 0.173 0.197325 0.192325 0.165091 0.106329 0.0401586 0.12059 0.318883 0.47833 0.550023
           0.551477 0.462448 0.309603 0.108657 0.173 0.47833 0.69324 0.819422 0.817403 0.691356 0.465378 0.160518
           0.197325 0.550023 0.819422 0.961479 0.959541 0.81798 0.548266 0.188515 0.192325 0.551477 0.817403 0.959541