efi_loader: definition of GetNextVariableName()

'vendor' is both an input and an output parameter. So it cannot be
constant.

Fixes: 0bda81bfdc5c ("efi_loader: use const efi_guid_t * for variable services")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/include/efi_api.h b/include/efi_api.h
index 4713da2..1c40ffc 100644
--- a/include/efi_api.h
+++ b/include/efi_api.h
@@ -272,7 +272,7 @@
 					    efi_uintn_t *data_size, void *data);
 	efi_status_t (EFIAPI *get_next_variable_name)(
 			efi_uintn_t *variable_name_size,
-			u16 *variable_name, const efi_guid_t *vendor);
+			u16 *variable_name, efi_guid_t *vendor);
 	efi_status_t (EFIAPI *set_variable)(u16 *variable_name,
 					    const efi_guid_t *vendor,
 					    u32 attributes,
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 37c3f15..3f27928 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -645,7 +645,7 @@
 				     efi_uintn_t *data_size, void *data);
 efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
 					       u16 *variable_name,
-					       const efi_guid_t *vendor);
+					       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, const void *data);
diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 3bec2d0..fe2f264 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -330,7 +330,7 @@
  */
 efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
 					       u16 *variable_name,
-					       const efi_guid_t *vendor)
+					       efi_guid_t *vendor)
 {
 	char *native_name, *variable;
 	ssize_t name_len, list_len;
@@ -598,7 +598,7 @@
  */
 static efi_status_t __efi_runtime EFIAPI
 efi_get_next_variable_name_runtime(efi_uintn_t *variable_name_size,
-				   u16 *variable_name, const efi_guid_t *vendor)
+				   u16 *variable_name, efi_guid_t *vendor)
 {
 	return EFI_UNSUPPORTED;
 }