hardcode numwords in semi-internal vli_isZero
diff --git a/include/tinycrypt/ecc.h b/include/tinycrypt/ecc.h
index 026febc..1205eb1 100644
--- a/include/tinycrypt/ecc.h
+++ b/include/tinycrypt/ecc.h
@@ -303,7 +303,7 @@
  * @param num_words IN -- number of words in the vli
  * @return 1 if vli == 0, 0 otherwise.
  */
-uECC_word_t uECC_vli_isZero(const uECC_word_t *vli, wordcount_t num_words);
+uECC_word_t uECC_vli_isZero(const uECC_word_t *vli);
 
 /*
  * @brief Check if 'point' is the point at infinity