Small documentation fixes

Signed-off-by: Felix Conway <felix.conway@arm.com>
diff --git a/ChangeLog.d/unify-errors.txt b/ChangeLog.d/unify-errors.txt
index 0ed56ba..f229f1b 100644
--- a/ChangeLog.d/unify-errors.txt
+++ b/ChangeLog.d/unify-errors.txt
@@ -3,5 +3,5 @@
      xxx is a module, e.g. X509 or SSL.
      MBEDTLS_ERR_xxx_BAD_INPUT_DATA    -> PSA_ERROR_INVALID_ARGUMENT
      MBEDTLS_ERR_xxx_ALLOC_FAILED      -> PSA_ERROR_INSUFFICIENT_MEMORY
-     MBEDTLS_ERR_xxx_VERIFY_FAILED     -> PSA_ERROR_INVALID_SIGNATURE
      MBEDTLS_ERR_xxx_BUFFER_TOO_SMALL  -> PSA_ERROR_BUFFER_TOO_SMALL
+     MBEDTLS_ERR_PKCS7_VERIFY_FAIL     -> PSA_ERROR_INVALID_SIGNATURE