When setting the "ports" property the value is duplicated but it's not
freed when the elements stops.
Reported by Valgrind (example run with "alsamidisrc ports=128:0"):
6 bytes in 1 blocks are definitely lost in loss record 30 of 1,911
at 0x4C2BBEF: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
by 0x5411528: g_malloc (gmem.c:94)
by 0x542A9FE: g_strdup (gstrfuncs.c:363)
by 0x775211E: gst_alsa_midi_src_set_property (gstalsamidisrc.c:284)
by 0x5184A4D: object_set_property (gobject.c:1439)
by 0x5184A4D: g_object_setv (gobject.c:2245)
by 0x51859DD: g_object_set_property (gobject.c:2529)
by 0x4F0474C: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1203.0)
by 0x4F065C8: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1203.0)
by 0x4F07557: ??? (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1203.0)
by 0x4EFE3EE: gst_parse_launch_full (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1203.0)
by 0x4EFE673: gst_parse_launchv_full (in /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0.1203.0)
https://bugzilla.gnome.org/show_bug.cgi?id=787683
alsamidisrc = GST_ALSA_MIDI_SRC (basesrc);
+ g_free (alsamidisrc->ports);
g_free (alsamidisrc->pfds);
g_free (alsamidisrc->buffer);
snd_midi_event_free (alsamidisrc->parser);