Staging: comedi: comedi_fops: Remove unused vmalloc.h header

Unused after commit d1843132 ("staging: comedi:
deprecate loading firmware with comedi_config").
Signed-off-by: Cheah Kok Cheong <thrust73@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/comedi_fops.c

@@ -30,7 +30,6 @@
 #include <linux/slab.h>
 #include <linux/poll.h>
 #include <linux/device.h>
-#include <linux/vmalloc.h>
 #include <linux/fs.h>
 #include "comedidev.h"
 #include <linux/cdev.h>