Change the incorrect "output" parameter help to "<type>_enumer.go"

stringer.go

@@ -48,7 +48,7 @@ var (
 	json            = flag.Bool("json", false, "if true, json marshaling methods will be generated. Default: false")
 	yaml            = flag.Bool("yaml", false, "if true, yaml marshaling methods will be generated. Default: false")
 	text            = flag.Bool("text", false, "if true, text marshaling methods will be generated. Default: false")
-	output          = flag.String("output", "", "output file name; default srcdir/<type>_string.go")
+	output          = flag.String("output", "", "output file name; default srcdir/<type>_enumer.go")
 	transformMethod = flag.String("transform", "noop", "enum item name transformation method. Default: noop")
 	trimPrefix      = flag.String("trimprefix", "", "transform each item name by removing a prefix. Default: \"\"")
 	lineComment     = flag.Bool("linecomment", false, "use line comment text as printed text when present")