perf/x86: Change test_aperfmperf() and test_intel() to static

Fixes the following sparse warnings:

 arch/x86/kernel/cpu/perf_event_msr.c:13:6: warning: symbol
 'test_aperfmperf' was not declared. Should it be static?

 arch/x86/kernel/cpu/perf_event_msr.c:18:6: warning: symbol
 'test_intel' was not declared. Should it be static?
Signed-off-by: Geliang Tang <geliangtang@163.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4588e8ab09638458f2451af572827108be3b4a36.1443123796.git.geliangtang@163.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/perf_event_msr.c

@@ -10,12 +10,12 @@ enum perf_msr_id {
 	PERF_MSR_EVENT_MAX,
 };
 
-bool test_aperfmperf(int idx)
+static bool test_aperfmperf(int idx)
 {
 	return boot_cpu_has(X86_FEATURE_APERFMPERF);
 }
 
-bool test_intel(int idx)
+static bool test_intel(int idx)
 {
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
 	    boot_cpu_data.x86 != 6)