xattr handlers: Simplify list operation

Change the list operation to only return whether or not an attribute
should be listed.  Copying the attribute names into the buffer is moved
to the callers.

Since the result only depends on the dentry and not on the attribute
name, we do not pass the attribute name to list operations.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/reiserfs/xattr_trusted.c b/fs/reiserfs/xattr_trusted.c
index a338adf..64b67aa 100644
--- a/fs/reiserfs/xattr_trusted.c
+++ b/fs/reiserfs/xattr_trusted.c
@@ -33,20 +33,9 @@
 	return reiserfs_xattr_set(d_inode(dentry), name, buffer, size, flags);
 }
 
-static size_t trusted_list(const struct xattr_handler *handler,
-			   struct dentry *dentry, char *list, size_t list_size,
-			   const char *name, size_t name_len)
+static bool trusted_list(struct dentry *dentry)
 {
-	const size_t len = name_len + 1;
-
-	if (!capable(CAP_SYS_ADMIN) || IS_PRIVATE(d_inode(dentry)))
-		return 0;
-
-	if (list && len <= list_size) {
-		memcpy(list, name, name_len);
-		list[name_len] = '\0';
-	}
-	return len;
+	return capable(CAP_SYS_ADMIN) && !IS_PRIVATE(d_inode(dentry));
 }
 
 const struct xattr_handler reiserfs_xattr_trusted_handler = {