efi_loader: efi_set_variable use const void *

The SetVariable() runtime service does not change the data passed to it.
So mark the parameter as constant.
Signed-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: NAlexander Graf <agraf@suse.de>

include/efi_api.h

@@ -230,7 +230,8 @@ struct efi_runtime_services {
 	efi_status_t (EFIAPI *set_variable)(u16 *variable_name,
 					    const efi_guid_t *vendor,
 					    u32 attributes,
-					    efi_uintn_t data_size, void *data);
+					    efi_uintn_t data_size,
+					    const void *data);
 	efi_status_t (EFIAPI *get_next_high_mono_count)(
 			uint32_t *high_count);
 	void (EFIAPI *reset_system)(enum efi_reset_type reset_type,

include/efi_loader.h

@@ -518,7 +518,7 @@ efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
 					       const efi_guid_t *vendor);
 efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
 				     const efi_guid_t *vendor, u32 attributes,
-				     efi_uintn_t data_size, void *data);
+				     efi_uintn_t data_size, const void *data);
 
 /*
  * See section 3.1.3 in the v2.7 UEFI spec for more details on

lib/efi_loader/efi_variable.c

@@ -254,7 +254,7 @@ efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
 /* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#SetVariable.28.29 */
 efi_status_t EFIAPI efi_set_variable(u16 *variable_name,
 				     const efi_guid_t *vendor, u32 attributes,
-				     efi_uintn_t data_size, void *data)
+				     efi_uintn_t data_size, const void *data)
 {
 	char *native_name = NULL, *val = NULL, *s;
 	efi_status_t ret = EFI_SUCCESS;