libnvdimm: Cleanup include of badblocks.h

* drivers/nvdimm/core.c doesn't use anything from badblocks.h on its own,
  thus including it isn't needed. There's indeed indirect use, via funcs
  in nd.h, but this one already includes badblocks.h.

* drivers/nvdimm/claim.c calls stuff from badblocks.h and therefore should
  include it on its own (instead of relying any other header doing that)

* drivers/nvdimm/btt.h doesn't really need anything from badblocks.h and
  can easily live with a forward declaration of struct badblocks (just
  having pointers to it, but not dereferencing it anywhere)

Signed-off-by: Enrico Weigelt <info@metux.net>
Link: https://lore.kernel.org/r/20201215163531.21446-1-info@metux.net
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/btt.h

@@ -7,7 +7,6 @@
 #ifndef _LINUX_BTT_H
 #define _LINUX_BTT_H
 
-#include <linux/badblocks.h>
 #include <linux/types.h>
 
 #define BTT_SIG_LEN 16
@@ -197,6 +196,8 @@ struct arena_info {
 	int log_index[2];
 };
 
+struct badblocks;
+
 /**
  * struct btt - handle for a BTT instance
  * @btt_disk:		Pointer to the gendisk for BTT device

drivers/nvdimm/claim.c

@@ -4,6 +4,7 @@
  */
 #include <linux/device.h>
 #include <linux/sizes.h>
+#include <linux/badblocks.h>
 #include "nd-core.h"
 #include "pmem.h"
 #include "pfn.h"

drivers/nvdimm/core.c

@@ -3,7 +3,6 @@
  * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
  */
 #include <linux/libnvdimm.h>
-#include <linux/badblocks.h>
 #include <linux/suspend.h>
 #include <linux/export.h>
 #include <linux/module.h>