[PATCH 4/6] char: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT

[Libin]

(*->vm_end - *->vm_start) >> PAGE_SHIFT operation is implemented
as a inline funcion vma_pages() in linux/mm.h, so using it.

Signed-off-by: Libin <huawei.libin at huawei.com>
---
 drivers/char/mspec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c
index e1f60f9..ed0703f 100644
--- a/drivers/char/mspec.c
+++ b/drivers/char/mspec.c
@@ -168,7 +168,7 @@ mspec_close(struct vm_area_struct *vma)
 	if (!atomic_dec_and_test(&vdata->refcnt))
 		return;
 
-	last_index = (vdata->vm_end - vdata->vm_start) >> PAGE_SHIFT;
+	last_index = vma_pages(vdata);
 	for (index = 0; index < last_index; index++) {
 		if (vdata->maddr[index] == 0)
 			continue;
-- 
1.8.2.1