new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ebeb94c..548ae31 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -714,7 +714,7 @@
  */
 void nfs_file_set_open_context(struct file *filp, struct nfs_open_context *ctx)
 {
-	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 	struct nfs_inode *nfsi = NFS_I(inode);
 
 	filp->private_data = get_nfs_open_context(ctx);
@@ -747,7 +747,7 @@
 
 static void nfs_file_clear_open_context(struct file *filp)
 {
-	struct inode *inode = filp->f_path.dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 	struct nfs_open_context *ctx = nfs_file_open_context(filp);
 
 	if (ctx) {