logger模块移入go-admin-core仓库，修改log用法暂时折中

fixme：后期要尽快改成统一的log处理方式

common/global/casbin.go

@@ -0,0 +1,15 @@
+package global
+
+import (
+	"github.com/casbin/casbin/v2"
+	"github.com/casbin/casbin/v2/log"
+)
+
+func LoadPolicy() (*casbin.SyncedEnforcer, error) {
+	if err := CasbinEnforcer.LoadPolicy(); err == nil {
+		return CasbinEnforcer, err
+	} else {
+		log.LogPrintf("casbin rbac_model or policy init error, message: %v \r\n", err.Error())
+		return nil, err
+	}
+}