When flushing the dvdspu, the even though presentation segment is set as 0, using pgs_presentation_segment_set_object_count, the array is still being created resulting in the below memory leak
Adding an extra condition to check if n_objects is != 0 then create the presentation objects

==11169== 40 bytes in 1 blocks are definitely lost in loss record 4,311 of 6,591
==11169==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==11169==    by 0x5D29610: g_malloc (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.4002.0)
==11169==    by 0x5D3F22D: g_slice_alloc (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.4002.0)
==11169==    by 0x5CF8C44: g_array_sized_new (in /lib/x86_64-linux-gnu/libglib-2.0.so.0.4002.0)
==11169==    by 0x20F43D8B: pgs_presentation_segment_set_object_count.isra.5 (gstspu-pgs.c:322)
==11169==    by 0x20F44A11: gstspu_pgs_flush (gstspu-pgs.c:799)
==11169==    by 0x20F3EBE8: gst_dvd_spu_flush_spu_info (gstdvdspu.c:270)
==11169==    by 0x20F3EC3A: gst_dvd_spu_clear (gstdvdspu.c:181)
==11169==    by 0x20F408C9: gst_dvd_spu_change_state (gstdvdspu.c:1229)
==11169==    by 0x57C02CC: gst_element_change_state (gstelement.c:2627)
==11169==    by 0x57C0ADB: gst_element_set_state_func (gstelement.c:2581)
==11169==    by 0x579F805: gst_bin_change_state_func (gstbin.c:2414)