new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/jfs/ioctl.c b/fs/jfs/ioctl.c
index bc555ff..93a1232 100644
--- a/fs/jfs/ioctl.c
+++ b/fs/jfs/ioctl.c
@@ -58,7 +58,7 @@
 
 long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-	struct inode *inode = filp->f_dentry->d_inode;
+	struct inode *inode = file_inode(filp);
 	struct jfs_inode_info *jfs_inode = JFS_IP(inode);
 	unsigned int flags;