do_sys_truncate(): switch to CLASS(filename)

Note that failures from filename_lookup() are final - ESTALE returned
by it means that retry had been done by filename_lookup() and it failed
there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

fs/open.c

@@ -129,25 +129,23 @@ EXPORT_SYMBOL_GPL(vfs_truncate);
 int do_sys_truncate(const char __user *pathname, loff_t length)
 {
 	unsigned int lookup_flags = LOOKUP_FOLLOW;
-	struct filename *name;
 	struct path path;
 	int error;
 
 	if (length < 0)	/* sorry, but loff_t says... */
 		return -EINVAL;
 
-	name = getname(pathname);
+	CLASS(filename, name)(pathname);
 retry:
 	error = filename_lookup(AT_FDCWD, name, lookup_flags, &path, NULL);
 	if (!error) {
 		error = vfs_truncate(&path, length);
 		path_put(&path);
+		if (retry_estale(error, lookup_flags)) {
+			lookup_flags |= LOOKUP_REVAL;
+			goto retry;
+		}
 	}
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
-	}
-	putname(name);
 	return error;
 }