Changelog entry for pacifying clang -Wdocumentation about \retval

Fixes #6960

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/ChangeLog.d/empty-retval-description.txt b/ChangeLog.d/empty-retval-description.txt
new file mode 100644
index 0000000..491adf5
--- /dev/null
+++ b/ChangeLog.d/empty-retval-description.txt
@@ -0,0 +1,3 @@
+Bugfix
+   * Silence warnings from clang -Wdocumentation about empty \retval
+     descriptions, which started appearing with Clang 15. Fixes #6960.