tools: Use hyphens instead of underscores for multi-word option names

tools/on_demand_service_tool.mm

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 25 matching lines @@
 void Usage(const std::string& me) {
   fprintf(stderr,
 "Usage: %s -L -l LABEL [OPTION]... COMMAND [ARG]...\n"
 "       %s -U -l LABEL\n"
 "Load and unload on-demand Mach services from launchd.\n"
 "\n"
 "  -L, --load                  load (submit) the job identified by --label;\n"
 "                              COMMAND must be specified\n"
 "  -U, --unload                unload (remove) the job identified by --label\n"
 "  -l, --label=LABEL           identify the job to launchd with LABEL\n"
-"  -m, --mach_service=SERVICE  register SERVICE with the bootstrap server\n"
+"  -m, --mach-service=SERVICE  register SERVICE with the bootstrap server\n"
 "      --help                  display this help and exit\n"
 "      --version               output version information and exit\n",
           me.c_str(),
           me.c_str());
   ToolSupport::UsageTail(me);
 }
 
 int OnDemandServiceToolMain(int argc, char* argv[]) {
   const std::string me(basename(argv[0]));
 
@@ skipping 21 matching lines @@
   struct {
     Operation operation;
     std::string job_label;
     std::vector<std::string> mach_services;
   } options = {};
 
   const struct option long_options[] = {
       {"load", no_argument, nullptr, kOptionLoadJob},
       {"unload", no_argument, nullptr, kOptionUnloadJob},
       {"label", required_argument, nullptr, kOptionJobLabel},
-      {"mach_service", required_argument, nullptr, kOptionMachService},
+      {"mach-service", required_argument, nullptr, kOptionMachService},
       {"help", no_argument, nullptr, kOptionHelp},
       {"version", no_argument, nullptr, kOptionVersion},
       {nullptr, 0, nullptr, 0},
   };
 
   int opt;
   while ((opt = getopt_long(argc, argv, "+LUl:m:", long_options, nullptr)) !=
           -1) {
     switch (opt) {
       case kOptionLoadJob:
@@ skipping 89 matching lines @@
     }
   }
 }
 
 }  // namespace
 }  // namespace crashpad
 
 int main(int argc, char* argv[]) {
   return crashpad::OnDemandServiceToolMain(argc, argv);
 }