staging: comedi: addi_apci_3120: remove unnecessary include

The <linux/sched.h> header is not needed by this driver. Remove the
include.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/addi_apci_3120.c

@@ -23,7 +23,6 @@
 
 #include <linux/module.h>
 #include <linux/pci.h>
-#include <linux/sched.h>
 #include <linux/interrupt.h>
 
 #include "../comedidev.h"