staging: comedi: dt3000: io_addr is a void __iomem *

The io_addr variable in struct dt3k_private is an ioremap'ed pci
resource and should be void __iomem * not a void *.

This quiets a lot of sparse warings for the writew and readw calls
like:

warning: incorrect type in argument 1 (different address spaces)
   expected void const volatile [noderef] <asn:2>*addr
   got void *<noident>

warning: incorrect type in argument 2 (different address spaces)
   expected void volatile [noderef] <asn:2>*addr
   got void *

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Mori Hess <fmhess@users.sourceforge.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt3000.c

@@ -252,7 +252,7 @@ struct dt3k_private {
 
 	struct pci_dev *pci_dev;
 	resource_size_t phys_addr;
-	void *io_addr;
+	void __iomem *io_addr;
 	unsigned int lock;
 	unsigned int ao_readback[2];
 	unsigned int ai_front;