hibernation: constify platform_hibernation_ops

Patch against mainline.

Changes since v1: added one hunk; no longer adding "const" qualifier to
pointers in platform_hibernation_ops after seeing
b4144e4f6e3b448d322095ca08af393682a69e33.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 657272e..491b81a 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -51,14 +51,14 @@
 
 static int hibernation_mode = HIBERNATION_SHUTDOWN;
 
-static struct platform_hibernation_ops *hibernation_ops;
+static const struct platform_hibernation_ops *hibernation_ops;
 
 /**
  * hibernation_set_ops - set the global hibernate operations
  * @ops: the hibernation operations to use in subsequent hibernation transitions
  */
 
-void hibernation_set_ops(struct platform_hibernation_ops *ops)
+void hibernation_set_ops(const struct platform_hibernation_ops *ops)
 {
 	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot
 	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore