staging: dgrp: Fix space prohibited before semicolon

This patch fixed "WARNING: space prohibited before semicoloni"
found by checkpatch.pl within dgrp_tty.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>