cpufreq-stats: Minor documentation fix

The cpufreq-stats code can no longer be built as a module, so it now
appears with square brackets in menuconfig.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 1aefc75b2449 (cpufreq: stats: Make the stats code non-modular)
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Documentation/cpu-freq/cpufreq-stats.txt

@@ -103,7 +103,7 @@ Config Main Menu
 	Power management options (ACPI, APM)  --->
 		CPU Frequency scaling  --->
 			[*] CPU Frequency scaling
-			<*>   CPU frequency translation statistics 
+			[*]   CPU frequency translation statistics
 			[*]     CPU frequency translation statistics details