Hardcode numwords in semi-internal vli_clear()
diff --git a/include/tinycrypt/ecc.h b/include/tinycrypt/ecc.h
index 1205eb1..59a7a89 100644
--- a/include/tinycrypt/ecc.h
+++ b/include/tinycrypt/ecc.h
@@ -484,7 +484,7 @@
  * @param vli IN -- very long integer
  * @param num_words IN -- number of words
  */
-void uECC_vli_clear(uECC_word_t *vli, wordcount_t num_words);
+void uECC_vli_clear(uECC_word_t *vli);
 
 /*
  * @brief check if it is a valid point in the curve