trace: Free symbols on program exit

This makes valgrind memleak checks with CONFIG_WPA_TRACE=y somewhat
cleaner.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

src/utils/os_unix.c

@@ -372,6 +372,7 @@ void os_program_deinit(void)
 	if (total)
 		wpa_printf(MSG_INFO, "MEMLEAK: total %lu bytes",
 			   (unsigned long) total);
+	wpa_trace_deinit();
 #endif /* WPA_TRACE */
 }