Reduce plugin init time as append in DCG causes up to 1% of compilati…

…on time

Summary:
DCG plugin loader init take up to 1% of compilation mainly due to unoptimized appendln (calls to property + toString)

This diff simplifies a call without loosing message context

Differential Revision: D63536703

fbshipit-source-id: 818ca64432281627a3e7fe9e63a182720d01acf8

compiler/common/src/main/kotlin/com/facebook/kotlin/compilerplugins/dataclassgenerate/configuration/CompilerConfigurationProperties.kt

@@ -21,7 +21,7 @@ object CompilerConfigurationProperties {
           CliOption(
               "mode",
               PluginMode.values().joinToString(prefix = "<", postfix = ">", separator = " | "),
-              "defines plugin mode, check ${PluginMode::name}",
+              "defines plugin mode, check PluginMode.kt enum for more details}",
               required = false),
           CompilerConfigurationKey("mode"),
           PluginMode.EXPLICIT)