new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index afd212c..3816270 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -137,7 +137,7 @@
 	if (obj->pages == NULL)
 		return -ENOMEM;
 
-	inode = obj->base.filp->f_path.dentry->d_inode;
+	inode = file_inode(obj->base.filp);
 	mapping = inode->i_mapping;
 	gfpmask |= mapping_gfp_mask(mapping);