Fix link_name for secp256k1_ec_seckey_negate

Author: junderw

secp256k1-sys/src/lib.rs

@@ -376,7 +376,7 @@ extern "C" {
     pub fn secp256k1_ec_privkey_negate(cx: *const Context,
                                        sk: *mut c_uchar) -> c_int;
 
-    #[cfg_attr(not(rust_secp_no_symbol_renaming), link_name = "rustsecp256k1_v0_3_1_ec_privkey_negate")]
+    #[cfg_attr(not(rust_secp_no_symbol_renaming), link_name = "rustsecp256k1_v0_3_1_ec_seckey_negate")]
     pub fn secp256k1_ec_seckey_negate(cx: *const Context,
                                       sk: *mut c_uchar) -> c_int;