[PATCH] x86_64: Sparse warnings fix.

 Fixes the following sparse warnings:

arch/x86_64/kernel/mce_amd.c:321:29: warning: Using plain integer as NULL pointer
arch/x86_64/kernel/mce_amd.c:410:41: warning: Using plain integer as NULL pointer
Signed-off-by: Luiz Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/mce_amd.c

@@ -320,7 +320,7 @@ static struct kobj_type threshold_ktype = {
 static __cpuinit int threshold_create_bank(unsigned int cpu, int bank)
 {
 	int err = 0;
-	struct threshold_bank *b = 0;
+	struct threshold_bank *b = NULL;
 
 #ifdef CONFIG_SMP
 	if (cpu_core_id[cpu] && shared_bank[bank]) {	/* symlink */
@@ -409,7 +409,7 @@ static __cpuinit void threshold_remove_bank(unsigned int cpu, int bank)
 	if (shared_bank[bank] && atomic_read(&b->kobj.kref.refcount) > 2) {
 		sprintf(name, "bank%i", bank);
 		sysfs_remove_link(&per_cpu(device_threshold, cpu).kobj, name);
-		per_cpu(threshold_banks, cpu)[bank] = 0;
+		per_cpu(threshold_banks, cpu)[bank] = NULL;
 	} else {
 		kobject_unregister(&b->kobj);
 		kfree(per_cpu(threshold_banks, cpu)[bank]);