Clarify potential ambiguity in changelog entry

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/ChangeLog.d/bignum-0-mod-2.txt b/ChangeLog.d/bignum-0-mod-2.txt
index 55e53e5..4a1ab16 100644
--- a/ChangeLog.d/bignum-0-mod-2.txt
+++ b/ChangeLog.d/bignum-0-mod-2.txt
@@ -1,4 +1,4 @@
 Bugfix
    * Fix a null pointer dereference when performing some operations on zero
-     represented with 0 limbs: mbedtls_mpi_mod_int() dividing by 2, or
-     mbedtls_mpi_write_string() in base 2.
+     represented with 0 limbs (specifically mbedtls_mpi_mod_int() dividing
+     by 2, and mbedtls_mpi_write_string() in base 2).