android/avdtp: Fix test /TP/SIG/SMG/BV-09-C

android/avdtp: Fix test /TP/SIG/SMG/BV-09-C

Test /TP/SIG/SMG/BV-09-C frees the session after set_configuration is
called causing the following backtrace:

Invalid read of size 8
   at 0x412B81: avdtp_sep_set_state (avdtp.c:846)
   by 0x413F3F: avdtp_set_configuration_resp (avdtp.c:2515)
   by 0x413F3F: avdtp_parse_resp (avdtp.c:2656)
   by 0x4159B7: session_cb (avdtp.c:2057)
   by 0x4E7E7FA: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.4200.2)
   by 0x4E7EB97: ??? (in /usr/lib64/libglib-2.0.so.0.4200.2)
   by 0x4E7EEC1: g_main_loop_run (in /usr/lib64/libglib-2.0.so.0.4200.2)
   by 0x4189D1: tester_run (tester.c:831)
   by 0x40C8C7: main (test-avdtp.c:1392)
 Address 0x58572b8 is 8 bytes inside a block of size 64 free'd
   at 0x4C2ACE9: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x4E8450E: g_free (in /usr/lib64/libglib-2.0.so.0.4200.2)
   by 0x4164B8: avdtp_unregister_sep (avdtp.c:3417)
   by 0x40CEA5: unregister_sep (test-avdtp.c:123)
   by 0x41704F: queue_remove_all (queue.c:387)
   by 0x4170B4: queue_destroy (queue.c:76)
   by 0x40CE54: destroy_context (test-avdtp.c:133)
   by 0x40CE54: context_quit (test-avdtp.c:145)
   by 0x40E74F: sep_setconf_cfm (test-avdtp.c:417)
   by 0x413F27: avdtp_set_configuration_resp (avdtp.c:2512)
   by 0x413F27: avdtp_parse_resp (avdtp.c:2656)
   by 0x4159B7: session_cb (avdtp.c:2057)
   by 0x4E7E7FA: g_main_context_dispatch (in /usr/lib64/libglib-2.0.so.0.4200.2)
   by 0x4E7EB97: ??? (in /usr/lib64/libglib-2.0.so.0.4200.2)