fix compiler errors

src/gpu/VirtualFluids_GPU/DataStructureInitializer/GridReaderGenerator/GridGenerator.cpp

@@ -549,8 +549,8 @@ void GridGenerator::initalValuesDomainDecompostion()
                         ////////////////////////////////////////////////////////////////////////////////////////
                         
                         
-                        int sendIDX = para->getParH(level)->sendProcessNeighborX[j].index[0];
-                        int recvIDX = para->getParH(level)->recvProcessNeighborX[j].index[0];
+                        // int sendIDX = para->getParH(level)->sendProcessNeighborX[j].index[0];
+                        // int recvIDX = para->getParH(level)->recvProcessNeighborX[j].index[0];
                     }
                 }
 

src/gpu/VirtualFluids_GPU/PreCollisionInteractor/PrecursorWriter.cu

@@ -301,7 +301,7 @@ std::string PrecursorWriter::makeFileName(std::string fileName, int level, int i
 
 void PrecursorWriter::getTaggedFluidNodes(Parameter *para, GridProvider* gridProvider)
 {
-    for(uint level=0; level<para->getMaxLevel(); level++)
+    for(size_t level=0; level<para->getMaxLevel(); level++)
     {
         if(outputVariable==OutputVariable::Velocities)
         {