mm/huge_memory.c: remove unused macro TRANSPARENT_HUGEPAGE_DEBUG_COW_…

…FLAG

Commit 4958e4d ("mm: thp: remove debug_cow switch") forgot to
remove TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG macro.  Remove it here.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michel Lespinasse <[email protected]>
Cc: Ralph Campbell <[email protected]>
Cc: Thomas Hellstrm (Intel) <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: William Kucharski <[email protected]>
Cc: Yang Shi <[email protected]>
Cc: yuleixzhang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

include/linux/huge_mm.h

@@ -87,9 +87,6 @@ enum transparent_hugepage_flag {
 	TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
 	TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
 	TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
-#ifdef CONFIG_DEBUG_VM
-	TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
-#endif
 };
 
 struct kobject;