Merge bitcoin-core/secp256k1#976: `secp256k1_schnorrsig_sign_internal…

…` should be static

7271387 Add missing static to secp256k1_schnorrsig_sign_internal (Elichai Turkel)

Pull request description:

  This function isn't used outside of this module so it should be declared static

ACKs for top commit:
  real-or-random:
    ACK 7271387
  jonasnick:
    ACK 7271387

Tree-SHA512: 6107a2c84c3e11ffd68de22a5288d989a3c71c2ec1ee4827c88f6165fc27ef8339d0f6740928540e8ccd03aff49a2a96149bf698ccebe6d6d8ad6e23e38e8838

src/modules/schnorrsig/main_impl.h

@@ -122,7 +122,7 @@ static void secp256k1_schnorrsig_challenge(secp256k1_scalar* e, const unsigned c
     secp256k1_scalar_set_b32(e, buf, NULL);
 }
 
-int secp256k1_schnorrsig_sign_internal(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg, size_t msglen, const secp256k1_keypair *keypair, secp256k1_nonce_function_hardened noncefp, void *ndata) {
+static int secp256k1_schnorrsig_sign_internal(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg, size_t msglen, const secp256k1_keypair *keypair, secp256k1_nonce_function_hardened noncefp, void *ndata) {
     secp256k1_scalar sk;
     secp256k1_scalar e;
     secp256k1_scalar k;