x86: clean up cpu capabilities accesses, common.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index bd111ce..57a46c3 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -409,7 +409,7 @@
 		lo |= 0x200000;
 		wrmsr(MSR_IA32_BBL_CR_CTL, lo, hi);
 		printk(KERN_NOTICE "CPU serial number disabled.\n");
-		clear_bit(X86_FEATURE_PN, c->x86_capability);
+		clear_cpu_cap(c, X86_FEATURE_PN);
 
 		/* Disabling the serial number may affect the cpuid level */
 		c->cpuid_level = cpuid_eax(0);