new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/video/msm/mdp.c b/drivers/video/msm/mdp.c
index f2566c1..113c787 100644
--- a/drivers/video/msm/mdp.c
+++ b/drivers/video/msm/mdp.c
@@ -261,7 +261,7 @@
 	if (f.file == NULL)
 		return -1;
 
-	if (MAJOR(f.file->f_dentry->d_inode->i_rdev) == FB_MAJOR) {
+	if (MAJOR(file_inode(f.file)->i_rdev) == FB_MAJOR) {
 		*start = info->fix.smem_start;
 		*len = info->fix.smem_len;
 	} else