bench: Port bitcoin-core/secp256k1#1796 to zkp-specific code

src/bench_bppp.c

@@ -29,6 +29,9 @@ static void bench_bppp(void* arg, int iters) {
 int main(void) {
     bench_bppp_data data;
     int iters = get_iters(32);
+    if (iters == 0) {
+        return EXIT_FAILURE;
+    }
 
     data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
 

src/bench_generator.c

@@ -50,6 +50,9 @@ static void bench_generator_generate_blinded(void* arg, int iters) {
 int main(void) {
     bench_generator_t data;
     int iters = get_iters(20000);
+    if (iters == 0) {
+        return EXIT_FAILURE;
+    }
 
     data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
 

src/bench_rangeproof.c

@@ -58,6 +58,9 @@ int main(void) {
 
     data.min_bits = 32;
     iters = data.min_bits*get_iters(32);
+    if (iters == 0) {
+        return EXIT_FAILURE;
+    }
 
     run_benchmark("rangeproof_verify_bit", bench_rangeproof, bench_rangeproof_setup, NULL, &data, 10, iters);
 

src/bench_whitelist.c

@@ -69,6 +69,9 @@ int main(void) {
     size_t n_keys = 30;
     secp256k1_scalar ssub;
     int iters = get_iters(5);
+    if (iters == 0) {
+        return EXIT_FAILURE;
+    }
 
     data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);