efi: Use NULL instead of 0 for pointer

Fix following sparse warnings:

drivers/firmware/efi/efivars.c:230:66: warning:
 Using plain integer as NULL pointer
drivers/firmware/efi/efi.c:236:27: warning:
 Using plain integer as NULL pointer
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

drivers/firmware/efi/efi.c

@@ -233,7 +233,7 @@ static __initdata efi_config_table_type_t common_tables[] = {
 	{SAL_SYSTEM_TABLE_GUID, "SALsystab", &efi.sal_systab},
 	{SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios},
 	{UGA_IO_PROTOCOL_GUID, "UGA", &efi.uga},
-	{NULL_GUID, NULL, 0},
+	{NULL_GUID, NULL, NULL},
 };
 
 static __init int match_config_table(efi_guid_t *guid,

drivers/firmware/efi/efivars.c

@@ -227,7 +227,7 @@ efivar_store_raw(struct efivar_entry *entry, const char *buf, size_t count)
 	memcpy(&entry->var, new_var, count);
 
 	err = efivar_entry_set(entry, new_var->Attributes,
-			       new_var->DataSize, new_var->Data, false);
+			       new_var->DataSize, new_var->Data, NULL);
 	if (err) {
 		printk(KERN_WARNING "efivars: set_variable() failed: status=%d\n", err);
 		return -EIO;