staging: dgnc: Fix unsigned value for less than zero

The "un->un_open_count" is unsigned variable, so it cannot
be less than zero.

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/dgnc/dgnc_tty.c b/drivers/staging/dgnc/dgnc_tty.c
index 8081621..f7409d9 100644 (file)
--- a/drivers/staging/dgnc/dgnc_tty.c
+++ b/drivers/staging/dgnc/dgnc_tty.c
@@ -1636,10 +1636,10 @@ static void dgnc_tty_close(struct tty_struct *tty, struct file *file)
                un->un_open_count = 1;
        }
 
-       if (--un->un_open_count < 0) {
+       if (un->un_open_count)
+               un->un_open_count--;
+       else
                APR(("bad serial port open count of %d\n", un->un_open_count));
-               un->un_open_count = 0;
-       }
 
        ch->ch_open_count--;