staging: comedi: pcmuio: remove unneeded include

The <linux/slab.h> header is no longer needed by this driver.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/pcmuio.c

@@ -75,7 +75,6 @@
 
 #include <linux/module.h>
 #include <linux/interrupt.h>
-#include <linux/slab.h>
 
 #include "../comedidev.h"