Parse numeric cmd-line args correctly.
am: 1362776c21

Change-Id: Ibbd98b6793f846e88e327bc26241e97c38367a6d
diff --git a/iface_fuzzer/ProtoFuzzerUtils.cpp b/iface_fuzzer/ProtoFuzzerUtils.cpp
index 6ae3019..b300121 100644
--- a/iface_fuzzer/ProtoFuzzerUtils.cpp
+++ b/iface_fuzzer/ProtoFuzzerUtils.cpp
@@ -129,10 +129,10 @@
         params.comp_specs_ = ExtractCompSpecs(optarg);
         break;
       case 'e':
-        params.exec_size_ = static_cast<size_t>(atoi(optarg));
+        params.exec_size_ = std::stoul(optarg);
         break;
       case 's':
-        params.seed_ = static_cast<uint64_t>(atoi(optarg));
+        params.seed_ = std::stoull(optarg);
         break;
       case 't':
         params.target_iface_ = optarg;