Open file repeatedly in gen_be_stage4.exe

[HappyKian]

When use_global_bin=.true. and num_bins2d .gt. 1, the lines 560 to 562

                 filename = 'sl_print.b'//ci//'.'//trim(variable)
                 open( unit=ounit, file=trim(filename), form='formatted', &
                 action='write', access='sequential', status='replace')

will be executed. In lines 507-509, there are the same codes as above, and there is not a close statement between them, which means the file filename will be opened more than once. This may cause an error in some compiler, such as ifort 17.0.5. According to the context, the code from lines 560 to 562 may be able to be deleted.