efi_loader: use list_count_nodes() in efi_protocols_per_handle()

Simplify the code by using the list_count_nodes() function.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index eedc5f3..4f52284 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2509,16 +2509,12 @@
 		return EFI_EXIT(EFI_INVALID_PARAMETER);
 
 	*protocol_buffer = NULL;
-	*protocol_buffer_count = 0;
 
 	efiobj = efi_search_obj(handle);
 	if (!efiobj)
 		return EFI_EXIT(EFI_INVALID_PARAMETER);
 
-	/* Count protocols */
-	list_for_each(protocol_handle, &efiobj->protocols) {
-		++*protocol_buffer_count;
-	}
+	*protocol_buffer_count = list_count_nodes(&efiobj->protocols);
 
 	/* Copy GUIDs */
 	if (*protocol_buffer_count) {