[PATCH v3 1/4] kernel.h: drop STACK_MAGIC macro

["Yury Norov (NVIDIA)" <yury.norov@gmail.com>]

The macro was introduced in 1994, v1.0.4, for stacks protection. Since
that, people found better ways to protect stacks, and now the macro is
only used by i915 selftests. Move it to a local header and drop from
the kernel.h.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Signed-off-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
---
 drivers/gpu/drm/i915/gt/selftest_ring_submission.c | 1 +
 drivers/gpu/drm/i915/i915_selftest.h               | 2 ++
 include/linux/kernel.h                             | 2 --
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_ring_submission.c b/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
index 87ceb0f374b6..600333ae6c8c 100644
--- a/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
+++ b/drivers/gpu/drm/i915/gt/selftest_ring_submission.c
@@ -3,6 +3,7 @@
  * Copyright © 2020 Intel Corporation
  */
 
+#include "i915_selftest.h"
 #include "intel_engine_pm.h"
 #include "selftests/igt_flush_test.h"
 
diff --git a/drivers/gpu/drm/i915/i915_selftest.h b/drivers/gpu/drm/i915/i915_selftest.h
index bdf3e22c0a34..72922028f4ba 100644
--- a/drivers/gpu/drm/i915/i915_selftest.h
+++ b/drivers/gpu/drm/i915/i915_selftest.h
@@ -26,6 +26,8 @@
 
 #include <linux/types.h>
 
+#define STACK_MAGIC	0xdeadbeef
+
 struct pci_dev;
 struct drm_i915_private;
 
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 5b46924fdff5..61d63c57bc2d 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -40,8 +40,6 @@
 
 #include <uapi/linux/kernel.h>
 
-#define STACK_MAGIC	0xdeadbeef
-
 struct completion;
 struct user;
 
-- 
2.43.0