Fix some typos

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/ChangeLog.d/cipher-delayed-output.txt b/ChangeLog.d/cipher-delayed-output.txt
index 0c8f7db..4ca3a0c 100644
--- a/ChangeLog.d/cipher-delayed-output.txt
+++ b/ChangeLog.d/cipher-delayed-output.txt
@@ -1,6 +1,6 @@
 API changes
-   * For multi-part AEAD operations with the Cipher module, calling
+   * For multi-part AEAD operations with the cipher module, calling
      mbedtls_cipher_finish() is now mandatory. Previously the documentation
      was unclear on this point, and this function happened to never do
-     anything with the currently implemented AEADs, so in practice is was
+     anything with the currently implemented AEADs, so in practice it was
      possible to skip calling it, which is no longer supported.