xen: annotate xen_set_identity_and_remap_chunk() with __init

Commit 5b8e7d80 removed the __init
annotation from xen_set_identity_and_remap_chunk(). Add it again.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>

arch/x86/xen/setup.c

@@ -368,7 +368,7 @@ static void __init xen_do_set_identity_and_remap_chunk(
  * pages. In the case of an error the underlying memory is simply released back
  * to Xen and not remapped.
  */
-static unsigned long xen_set_identity_and_remap_chunk(
+static unsigned long __init xen_set_identity_and_remap_chunk(
         const struct e820entry *list, size_t map_size, unsigned long start_pfn,
 	unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pfn,
 	unsigned long *identity, unsigned long *released)