userns: rename is_owner_or_cap to inode_owner_or_capable

And give it a kernel-doc comment.

[akpm@linux-foundation.org: btrfs changed in linux-next]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/xattr.c b/fs/xattr.c
index 01bb813..a19acdb 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -59,7 +59,7 @@
 		if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
 			return -EPERM;
 		if (S_ISDIR(inode->i_mode) && (inode->i_mode & S_ISVTX) &&
-		    (mask & MAY_WRITE) && !is_owner_or_cap(inode))
+		    (mask & MAY_WRITE) && !inode_owner_or_capable(inode))
 			return -EPERM;
 	}