new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 78bde32..edb42ea 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -97,7 +97,7 @@
 
 static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(file);
 	loff_t len, vma_len;
 	int ret;
 	struct hstate *h = hstate_file(file);