Add missing RC4 function pointers from AES-CTR-HMAC AEADs.

I think these two things were written at the same time and so the
AES-CTR-HMAC AEADs never explicitly set these values.

Change-Id: I0a142ad2b0fb9e893e290c1def5e5c6b193a3cc8

crypto/cipher/e_aes.c

@@ -1749,6 +1749,7 @@ static const EVP_AEAD aead_aes_128_ctr_hmac_sha256 = {
     aead_aes_ctr_hmac_sha256_cleanup,
     aead_aes_ctr_hmac_sha256_seal,
     aead_aes_ctr_hmac_sha256_open,
+    NULL /* get_rc4_state */,
 };
 
 static const EVP_AEAD aead_aes_256_ctr_hmac_sha256 = {
@@ -1762,6 +1763,7 @@ static const EVP_AEAD aead_aes_256_ctr_hmac_sha256 = {
     aead_aes_ctr_hmac_sha256_cleanup,
     aead_aes_ctr_hmac_sha256_seal,
     aead_aes_ctr_hmac_sha256_open,
+    NULL /* get_rc4_state */,
 };
 
 const EVP_AEAD *EVP_aead_aes_128_ctr_hmac_sha256(void) {