[PATCH] powerpc/mm: Fix hugetlb page initialization

[Sachin Sant]

This patch fixes a regression by using correct kernel config variable
for HUGETLB_PAGE_SIZE_VARIABLE.

Without this huge pages are disabled during kernel boot.
[0.309496] hugetlbfs: disabling because there are no supported hugepage sizes

Fixes: c5710cd20735 ("powerpc/mm: cleanup HPAGE_SHIFT setup")
Reported-by: Sachin Sant <sachinp at linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Tested-by: Sachin Sant <sachinp at linux.ibm.com>

---
diff -Narup a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
--- a/arch/powerpc/mm/hugetlbpage.c	2019-05-06 07:30:11.711092744 -0400
+++ b/arch/powerpc/mm/hugetlbpage.c	2019-05-06 07:29:32.963433258 -0400
@@ -640,7 +640,7 @@ static int __init hugetlbpage_init(void)
 			pgtable_cache_add(PTE_T_ORDER);
 	}
 
-	if (IS_ENABLED(HUGETLB_PAGE_SIZE_VARIABLE))
+	if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
 		hugetlbpage_init_default();
 
 	return 0;