Update variable.cpp

I remembered that I forgot to remove these commented printf() calls.

src/variable.cpp

@@ -771,10 +771,8 @@ int Variable::next(int narg, char **arg)
         error->one(FLERR,"Unexpected error while incrementing uloop style variable. "
                    "Please contact the LAMMPS developers.");
 
-      //printf("READ %d %d\n",universe->me,nextindex);
       fp = fopen("tmp.lammps.variable.lock","w");
       fprintf(fp,"%d\n",nextindex+1);
-      //printf("WRITE %d %d\n",universe->me,nextindex+1);
       fclose(fp);
       fp = nullptr;
       rename("tmp.lammps.variable.lock","tmp.lammps.variable");