schnorrsig bench: Suppress a stupid warning in MSVC

Author: real-or-random

src/modules/schnorrsig/bench_impl.h

@@ -91,10 +91,12 @@ void run_schnorrsig_bench(int iters, int argc, char** argv) {
         free((void *)data.msgs[i]);
         free((void *)data.sigs[i]);
     }
-    free(data.keypairs);
-    free(data.pk);
-    free(data.msgs);
-    free(data.sigs);
+
+    /* Casting to (void *) avoids a stupid warning in MSVC. */
+    free((void *)data.keypairs);
+    free((void *)data.pk);
+    free((void *)data.msgs);
+    free((void *)data.sigs);
 
     secp256k1_context_destroy(data.ctx);
 }