fixed a compilation problem if LIGHTCONE_PARTICLES_GROUPS was used without SUBFIND_HBT

src/subfind/subfind_density.cc

@@ -151,7 +151,7 @@ class subdens_comm : public generic_comm<subdens_in, subdens_out, T_tree, T_doma
           {
             int p, type;
             double mass, r2;
-            particle_data *P;
+            typename T_partset::pdata *P;
 
             if(no < Tree->MaxPart) /* single particle */
               {

src/subfind/subfind_findlinkngb.cc

@@ -122,7 +122,7 @@ class nearest_comm : public generic_comm<nearest_in, nearest_out, T_tree, T_doma
           {
             if(no < Tree->MaxPart) /* single particle */
               {
-                particle_data *P = Tree->get_Pp(no, shmrank);
+                auto *P = Tree->get_Pp(no, shmrank);
 
                 no = Tree->get_nextnodep(shmrank)[no]; /* note: here shmrank cannot change */
 

src/subfind/subfind_nearesttwo.cc

@@ -189,7 +189,7 @@ class sngb_comm : public generic_comm<sngb_in, sngb_out, T_tree, T_domain, T_par
           {
             if(no < Tree->MaxPart) /* single particle */
               {
-                particle_data *P = Tree->get_Pp(no, shmrank);
+                auto *P          = Tree->get_Pp(no, shmrank);
                 subfind_data *PS = Tree->get_PSp(no, shmrank);
 
                 no = Tree->get_nextnodep(shmrank)[no]; /* note: here shmrank cannot change */