task_allocator: Use config switches instead of magic defines

Replace __HAVE_ARCH_TASK_ALLOCATOR and __HAVE_ARCH_THREAD_ALLOCATOR
with proper config switches.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20120505150142.371309416@linutronix.de
diff --git a/kernel/fork.c b/kernel/fork.c
index 7590bd6..a1793e4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -111,7 +111,7 @@
 	return total;
 }
 
-#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
 static struct kmem_cache *task_struct_cachep;
 
 static inline struct task_struct *alloc_task_struct_node(int node)
@@ -128,8 +128,7 @@
 }
 #endif
 
-#ifndef __HAVE_ARCH_THREAD_INFO_ALLOCATOR
-
+#ifndef CONFIG_ARCH_THREAD_INFO_ALLOCATOR
 void __weak arch_release_thread_info(struct thread_info *ti) { }
 
 /*
@@ -243,7 +242,7 @@
 
 void __init fork_init(unsigned long mempages)
 {
-#ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
 #ifndef ARCH_MIN_TASKALIGN
 #define ARCH_MIN_TASKALIGN	L1_CACHE_BYTES
 #endif