s390/dcssblk: fix virtual vs physical address confusion

Fix virtual vs physical address confusion. This does not fix a bug
since virtual and physical address spaces are currently the same.

dax_direct_access() should receive a virtual kernel address in kaddr.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

drivers/s390/block/dcssblk.c

@@ -919,7 +919,7 @@ __dcssblk_direct_access(struct dcssblk_dev_info *dev_info, pgoff_t pgoff,
 
 	dev_sz = dev_info->end - dev_info->start + 1;
 	if (kaddr)
-		*kaddr = (void *) dev_info->start + offset;
+		*kaddr = __va(dev_info->start + offset);
 	if (pfn)
 		*pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset),
 				PFN_DEV|PFN_SPECIAL);