cpufreq: intel_pstate: fix intel_pstate_exit_perf_limits() prototype

The addition of the generic governor support marked the
intel_pstate_exit_perf_limits as inline(), which fixed a warning,
but it introduced another warning:

drivers/cpufreq/intel_pstate.c: In function ‘intel_pstate_exit_perf_limits’:
drivers/cpufreq/intel_pstate.c:483:1: error: no return statement in function returning non-void [-Werror=return-type]

This changes it back to a 'void' return type, and changes the
corresponding intel_pstate_init_acpi_perf_limits() function to
be inline as well for consistency.

Fixes: 001c76f05b (cpufreq: intel_pstate: Generic governors support)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/intel_pstate.c

@@ -479,11 +479,11 @@ static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
 }
 
 #else
-static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
+static inline void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
 {
 }
 
-static inline int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+static inline void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
 {
 }
 #endif