Changelog: Brought forward changelog changes from #4716308

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/ChangeLog.d/error-unification.txt b/ChangeLog.d/error-unification.txt
index bcf5ba1..1f8e8af 100644
--- a/ChangeLog.d/error-unification.txt
+++ b/ChangeLog.d/error-unification.txt
@@ -7,5 +7,6 @@
      between -32767 and -1 as before.
 
 Removals
-   * Remove mbedtls_low_level_sterr() and mbedtls_high_level_strerr(),
+   * Remove mbedtls_low_level_strerr() and mbedtls_high_level_strerr(),
      since these concepts no longer exists. There is just mbedtls_strerror().
+