x86/efi: Free efi_pgd with free_pages()

The efi_pgd is allocated as PGD_ALLOCATION_ORDER pages and therefore must
also be freed as PGD_ALLOCATION_ORDER pages with free_pages().

Fixes: d9e9a64 ("x86/mm/pti: Allocate a separate user PGD")
Signed-off-by: Waiman Long <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: Dave Hansen <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

Author: Waiman-Long

arch/x86/platform/efi/efi_64.c

@@ -227,7 +227,7 @@ int __init efi_alloc_page_tables(void)
 	if (!pud) {
 		if (CONFIG_PGTABLE_LEVELS > 4)
 			free_page((unsigned long) pgd_page_vaddr(*pgd));
-		free_page((unsigned long)efi_pgd);
+		free_pages((unsigned long)efi_pgd, PGD_ALLOCATION_ORDER);
 		return -ENOMEM;
 	}