kmemcheck: remove multiple ifdef'd definitions of the same global variable

Multiple ifdef'd definitions of the same global variable is ugly and
error-prone. Fix that up.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

arch/x86/mm/kmemcheck/kmemcheck.c

@@ -67,17 +67,19 @@ int __init kmemcheck_init(void)
 early_initcall(kmemcheck_init);
 
 #ifdef CONFIG_KMEMCHECK_DISABLED_BY_DEFAULT
-int kmemcheck_enabled = 0;
+#  define KMEMCHECK_ENABLED 0
 #endif
 
 #ifdef CONFIG_KMEMCHECK_ENABLED_BY_DEFAULT
-int kmemcheck_enabled = 1;
+#  define KMEMCHECK_ENABLED 1
 #endif
 
 #ifdef CONFIG_KMEMCHECK_ONESHOT_BY_DEFAULT
-int kmemcheck_enabled = 2;
+#  define KMEMCHECK_ENABLED 2
 #endif
 
+int kmemcheck_enabled = KMEMCHECK_ENABLED;
+
 /*
  * We need to parse the kmemcheck= option before any memory is allocated.
  */