staging: dgnc: remove tracing prints in dgnc_tty.c

Remove tracing prints in dgnc_tty_send_xchar. The same functionality
could be achieved by using ftrace.

Signed-off-by: Abhishek Bhardwaj <abshkbh@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>