libwally: fix hmac_sha256 name clash.

This is a workaround; eventually libwally will be a nice shared library that
we won't have to bundle, and clashing with internal symbols won't be
a problem.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

libwally-core/1README

@@ -0,0 +1 @@
+Stolen from 3b025127cbf11912f8b95e7ff3c905d74e8433ce, with hmac_256 -> hmac_256_internal to avoid name clash

libwally-core/src/hmac.c

@@ -8,7 +8,7 @@
 #define SHA_T sha256
 #define SHA_CTX_MEMBER u32
 #define SHA_PRE(name) sha256 ## name
-#define HMAC_FUNCTION hmac_sha256
+#define HMAC_FUNCTION hmac_sha256_internal
 #define WALLY_HMAC_FUNCTION wally_hmac_sha256
 #include "hmac.inl"
 

libwally-core/src/hmac.h

@@ -5,7 +5,7 @@ struct sha256;
 struct sha512;
 
 /**
- * hmac_sha256 - Compute an HMAC using SHA-256
+ * hmac_sha256_internal - Compute an HMAC using SHA-256
  *
  * @sha: Destination for the resulting HMAC.
  * @key: The key for the hash
@@ -13,7 +13,7 @@ struct sha512;
  * @msg: The message to hash
  * @msg_len: The length of @msg in bytes.
  */
-void hmac_sha256(struct sha256 *sha,
+void hmac_sha256_internal(struct sha256 *sha,
                  const unsigned char *key, size_t key_len,
                  const unsigned char *msg, size_t msg_len);