Remove unnecessary calls to ithread_exit

The ithread_exit wrapper function behaves inconsistently across
platforms; on windows, the argument is a thread handle, denoting
the thread that will be exited. On pthreads, ithread_exit only
terminates the current thread, not any other thread.

These both calls are at the end of each thread function (and the one
with a non-null parameter refers to the handle of the thread itself),
so the thread will exit immediately anyway.

Change-Id: I21e43c56874729452bd80b28ff351e3c5d3f087e
diff --git a/decoder/ih264d_thread_parse_decode.c b/decoder/ih264d_thread_parse_decode.c
index 910183c..f3da270 100644
--- a/decoder/ih264d_thread_parse_decode.c
+++ b/decoder/ih264d_thread_parse_decode.c
@@ -633,8 +633,6 @@
                               ps_dec->u4_fmt_conv_num_rows);
         ps_dec->u4_fmt_conv_cur_row += ps_dec->u4_fmt_conv_num_rows;
     }
-
-    ithread_exit(0);
 }
 
 void ih264d_signal_decode_thread(dec_struct_t *ps_dec)
diff --git a/test/decoder/main.c b/test/decoder/main.c
index 937515e..8c9e885 100644
--- a/test/decoder/main.c
+++ b/test/decoder/main.c
@@ -1612,9 +1612,6 @@
     }
     ps_app_ctx->disp_deinit(ps_app_ctx->pv_disp_ctx);
 
-    /* destroy the display thread */
-    ithread_exit(ps_app_ctx->display_thread_handle);
-
     return 0;
 }