staging: comedi: serial2002: Fix bare unsigned styling issue

checkpatch.pl warns about a bare unsigned. Add type int to make
explicit and suit the coding style.

Signed-off-by Chris Cesare <chris.cesare@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/serial2002.c

@@ -95,7 +95,7 @@ struct serial_data {
 #define S2002_CFG_SIGN(x)		(((x) >> 13) & 0x1)
 #define S2002_CFG_BASE(x)		(((x) >> 14) & 0xfffff)
 
-static long serial2002_tty_ioctl(struct file *f, unsigned op,
+static long serial2002_tty_ioctl(struct file *f, unsigned int op,
 				 unsigned long param)
 {
 	if (f->f_op->unlocked_ioctl)