x86: silence section mismatch warning - get_local_pda

Take out part of get_local_pda referencing __init function (free_bootmem)
to new (static) function marked as __ref. It's safe to do because free_bootmem
is called before __init sections are dropped.

WARNING: vmlinux.o(.cpuinit.text+0x3cd7): Section mismatch in reference from the function get_local_pda() to the function .init.text:free_bootmem()
The function __cpuinit get_local_pda() references
a function __init free_bootmem().
If free_bootmem is only used by get_local_pda then
annotate free_bootmem with a matching annotation.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/smpboot.c

@@ -756,6 +756,14 @@ static void __cpuinit do_fork_idle(struct work_struct *work)
 }
 
 #ifdef CONFIG_X86_64
+
+/* __ref because it's safe to call free_bootmem when after_bootmem == 0. */
+static void __ref free_bootmem_pda(struct x8664_pda *oldpda)
+{
+	if (!after_bootmem)
+		free_bootmem((unsigned long)oldpda, sizeof(*oldpda));
+}
+
 /*
  * Allocate node local memory for the AP pda.
  *
@@ -784,8 +792,7 @@ int __cpuinit get_local_pda(int cpu)
 
 	if (oldpda) {
 		memcpy(newpda, oldpda, size);
-		if (!after_bootmem)
-			free_bootmem((unsigned long)oldpda, size);
+		free_bootmem_pda(oldpda);
 	}
 
 	newpda->in_bootmem = 0;