mm/memory-failure: remove MF_MSG_SLAB

Since commit 46df8e73 ("mm: free up PG_slab"), MF_MSG_SLAB becomes
unused.  Remove it.  No functional change intended.

Link: https://lkml.kernel.org/r/20240612071835.157004-3-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/mm.h

@@ -4067,7 +4067,6 @@ enum mf_result {
 enum mf_action_page_type {
 	MF_MSG_KERNEL,
 	MF_MSG_KERNEL_HIGH_ORDER,
-	MF_MSG_SLAB,
 	MF_MSG_DIFFERENT_COMPOUND,
 	MF_MSG_HUGE,
 	MF_MSG_FREE_HUGE,

include/ras/ras_event.h

@@ -356,7 +356,6 @@ TRACE_EVENT(aer_event,
 #define MF_PAGE_TYPE		\
 	EM ( MF_MSG_KERNEL, "reserved kernel page" )			\
 	EM ( MF_MSG_KERNEL_HIGH_ORDER, "high-order kernel page" )	\
-	EM ( MF_MSG_SLAB, "kernel slab page" )				\
 	EM ( MF_MSG_DIFFERENT_COMPOUND, "different compound page after locking" ) \
 	EM ( MF_MSG_HUGE, "huge page" )					\
 	EM ( MF_MSG_FREE_HUGE, "free huge page" )			\

mm/memory-failure.c

@@ -911,7 +911,6 @@ static const char *action_name[] = {
 static const char * const action_page_types[] = {
 	[MF_MSG_KERNEL]			= "reserved kernel page",
 	[MF_MSG_KERNEL_HIGH_ORDER]	= "high-order kernel page",
-	[MF_MSG_SLAB]			= "kernel slab page",
 	[MF_MSG_DIFFERENT_COMPOUND]	= "different compound page after locking",
 	[MF_MSG_HUGE]			= "huge page",
 	[MF_MSG_FREE_HUGE]		= "free huge page",