new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index 04a371a..054e26e 100644
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -202,7 +202,7 @@
 	WARN_ON(gt->pages);
 
 	/* This is the shared memory object that backs the GEM resource */
-	inode = gt->gem.filp->f_path.dentry->d_inode;
+	inode = file_inode(gt->gem.filp);
 	mapping = inode->i_mapping;
 
 	gt->pages = kmalloc(pages * sizeof(struct page *), GFP_KERNEL);