x86, watchdog: Compile fix when CONFIG_LOCAL_APIC not enabled

When adjusting the code to handle removing the old nmi watchdog,
I forgot to consider the compile case when the local apic is not
enabled.

This change fixes the following build error:

  arch/x86/kernel/apic/hw_nmi.c:28:6: error: redefinition of ‘touch_nmi_watchdog’

Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Rakib Mullick <rakib.mullick@gmail.com>
LKML-Reference: <20101213153719.GD18577@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/hw_nmi.c

@@ -17,6 +17,7 @@
 #include <linux/nmi.h>
 #include <linux/module.h>
 
+#ifdef ARCH_HAS_NMI_WATCHDOG
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 u64 hw_nmi_get_sample_period(void)
 {
@@ -31,6 +32,8 @@ void touch_nmi_watchdog(void)
 }
 EXPORT_SYMBOL(touch_nmi_watchdog);
 #endif
+#endif
+
 #ifdef arch_trigger_all_cpu_backtrace
 /* For reliability, we're prepared to waste bits here. */
 static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;