efivars: Stop passing a struct argument to efivar_validate()

In preparation for compat support, we can't assume that user variable
object is represented by a 'struct efi_variable'. Convert the validation
functions to take the variable name as an argument, which is the only
piece of the struct that was ever used anyway.

Cc: Mike Waychison <mikew@google.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 82d0abb..6a4d8e2 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1039,8 +1039,10 @@
  * and we use a page for reading/writing.
  */
 
+#define EFI_VAR_NAME_LEN	1024
+
 struct efi_variable {
-	efi_char16_t  VariableName[1024/sizeof(efi_char16_t)];
+	efi_char16_t  VariableName[EFI_VAR_NAME_LEN/sizeof(efi_char16_t)];
 	efi_guid_t    VendorGuid;
 	unsigned long DataSize;
 	__u8          Data[1024];
@@ -1122,7 +1124,7 @@
 struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
 				       struct list_head *head, bool remove);
 
-bool efivar_validate(struct efi_variable *var, u8 *data, unsigned long len);
+bool efivar_validate(efi_char16_t *var_name, u8 *data, unsigned long len);
 
 extern struct work_struct efivar_work;
 void efivar_run_worker(void);