more file_inode() open-coded instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
index c541ab8..b505a14 100644
--- a/fs/ext4/indirect.c
+++ b/fs/ext4/indirect.c
@@ -1606,7 +1606,7 @@
 
 int ext4_ind_punch_hole(struct file *file, loff_t offset, loff_t length)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	struct super_block *sb = inode->i_sb;
 	ext4_lblk_t first_block, stop_block;
 	struct address_space *mapping = inode->i_mapping;