use new _eckey_pubkey_serialize{33,65} functions in public API

Author: theStack

src/secp256k1.c

@@ -280,10 +280,14 @@ int secp256k1_ec_pubkey_serialize(const secp256k1_context* ctx, unsigned char *o
     ARG_CHECK(pubkey != NULL);
     ARG_CHECK((flags & SECP256K1_FLAGS_TYPE_MASK) == SECP256K1_FLAGS_TYPE_COMPRESSION);
     if (secp256k1_pubkey_load(ctx, &Q, pubkey)) {
-        ret = secp256k1_eckey_pubkey_serialize(&Q, output, &len, !!(flags & SECP256K1_FLAGS_BIT_COMPRESSION));
-        if (ret) {
-            *outputlen = len;
+        if (flags & SECP256K1_FLAGS_BIT_COMPRESSION) {
+            secp256k1_eckey_pubkey_serialize33(&Q, output);
+            *outputlen = 33;
+        } else {
+            secp256k1_eckey_pubkey_serialize65(&Q, output);
+            *outputlen = 65;
         }
+        ret = 1;
     }
     return ret;
 }