validation CHANGE validating single module data

... instead of module array. It simplifies the API
considerably and in case several modules need to
be validated, the function can be called repeatedly
without any performance impact.
diff --git a/src/parser_data.h b/src/parser_data.h
index f0d5a29..e12b65e 100644
--- a/src/parser_data.h
+++ b/src/parser_data.h
@@ -254,16 +254,15 @@
 LY_ERR lyd_validate(struct lyd_node **tree, const struct ly_ctx *ctx, int val_opts);
 
 /**
- * @brief Fully validate a data tree.
+ * @brief Fully validate a data tree of a module.
  *
  * @param[in,out] tree Data tree to recursively validate. May be changed by validation.
- * @param[in] modules Array of modules to validate.
- * @param[in] mod_count Number of @p modules.
+ * @param[in] module Module whose data (and schema restrictions) to validate.
  * @param[in] val_opts Validation options (@ref datavalidationoptions).
  * @return LY_SUCCESS on success.
  * @return LY_ERR error on error.
  */
-LY_ERR lyd_validate_modules(struct lyd_node **tree, const struct lys_module **modules, int mod_count, int val_opts);
+LY_ERR lyd_validate_module(struct lyd_node **tree, const struct lys_module *module, int val_opts);
 
 /**
  * @brief Validate an RPC/action, notification, or RPC/action reply.