Fix section title underlining in the release notes

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 498ffbc..e96f144 100644 (file)
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -89,7 +89,7 @@ Changes to the MIPS Target
 During this release ...
 
 Changes to the Hexagon Target
---------------------------
+-----------------------------
 
 * The Hexagon target now supports V68/HVX ISA.