Minor fix in Hermes Inspector cli tool help message

Summary:
Chrome recently changed schema from 'chrome-devtools' to just 'devtools',
this change updates Hermes inspector cli tool usage string to reflect that change

Changelog: Minor fix in Hermes Inspector cli tool help message

Reviewed By: dulinriley

Differential Revision: D22557806

fbshipit-source-id: 95ec9cbaac445e105e7e92aec2b6c4e5a7d7924f

Author: Oleg Bogdanov

ReactCommon/hermes/inspector/chrome/cli/main.cpp

@@ -38,7 +38,7 @@ debug server. For instance, running this:
 will run a WebSocket server on port 9999 that debugs script.js in Hermes. Chrome
 can connect to this debugging session using a URL like this:
 
-  chrome-devtools://devtools/bundled/inspector.html?experiments=false&v8only=true&ws=127.0.0.1:9999
+  devtools://devtools/bundled/inspector.html?experiments=false&v8only=true&ws=127.0.0.1:9999
 
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