update ChangLog per comments

Signed-off-by: Jeffrey Martin <Jeffrey_Martin@rapid7.com>
diff --git a/ChangeLog b/ChangeLog
index 09ab3db..26965bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -5,10 +5,11 @@
 Bugfix
    * Run the AD too long test only if MBEDTLS_CCM_ALT is not defined.
      Raised as a comment in #1996.
-   * Extend register cleanup needed on MIPS assembly optimizations. Adds hi, lo
-     registers hints to the compiler for usage with the embedded MIPS assembly.
-     Reported in #1722, fix suggested by @aurel32 and submitted
-     by Jeffrey Martin, #1949.
+   * Fix clobber list in MIPS assembly for large integer multiplication.
+     Previously, this could lead to functionally incorrect assembly being
+     produced by some optimizing compilers, showing up as failures in
+     e.g. RSA or ECC signature operations. Reported in #1722, fix suggested
+     by @aurel32 and submitted by Jeffrey Martin.
 
 = mbed TLS 2.7.9 branch released 2018-12-21