new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c
index 85156dd..65a8d96 100644
--- a/drivers/char/dtlk.c
+++ b/drivers/char/dtlk.c
@@ -125,7 +125,7 @@
 static ssize_t dtlk_read(struct file *file, char __user *buf,
 			 size_t count, loff_t * ppos)
 {
-	unsigned int minor = iminor(file->f_path.dentry->d_inode);
+	unsigned int minor = iminor(file_inode(file));
 	char ch;
 	int i = 0, retries;
 
@@ -177,7 +177,7 @@
 	}
 #endif
 
-	if (iminor(file->f_path.dentry->d_inode) != DTLK_MINOR)
+	if (iminor(file_inode(file)) != DTLK_MINOR)
 		return -EINVAL;
 
 	while (1) {