Fix after PR comments

1. Don't set IV onECB
2. Fix style issues
3. reduce number of tests
diff --git a/library/cipher_wrap.c b/library/cipher_wrap.c
index 893490a..6dd8c5d 100644
--- a/library/cipher_wrap.c
+++ b/library/cipher_wrap.c
@@ -258,7 +258,7 @@
     MBEDTLS_MODE_ECB,
     128,
     "AES-128-ECB",
-    16,
+    0,
     0,
     16,
     &aes_info
@@ -269,7 +269,7 @@
     MBEDTLS_MODE_ECB,
     192,
     "AES-192-ECB",
-    16,
+    0,
     0,
     16,
     &aes_info
@@ -280,7 +280,7 @@
     MBEDTLS_MODE_ECB,
     256,
     "AES-256-ECB",
-    16,
+    0,
     0,
     16,
     &aes_info