rust-core: fix typo in comment
Differential Revision: https://phab.mercurial-scm.org/D7895
--- a/rust/hg-core/src/revlog.rs Tue Jan 14 18:59:49 2020 -0800
+++ b/rust/hg-core/src/revlog.rs Thu Jan 16 00:30:08 2020 +0800
@@ -14,7 +14,7 @@
/// Marker expressing the absence of a parent
///
/// Independently of the actual representation, `NULL_REVISION` is guaranteed
-/// to be smaller that all existing revisions.
+/// to be smaller than all existing revisions.
pub const NULL_REVISION: Revision = -1;
/// Same as `mercurial.node.wdirrev`