Simplify helpers under line cap

lib/persist.sh

@@ -9,24 +9,17 @@ IPF_PERSIST_SH_LOADED=1
 : "${IPF_SKIP_PERSIST:=0}"
 
 persist_available() {
-  [[ ${IPF_SKIP_PERSIST} == 1 ]] && return 0
-  command_is_available "${NETFILTER_PERSISTENT_BIN}"
+  [[ ${IPF_SKIP_PERSIST} == 1 ]] || command_is_available "${NETFILTER_PERSISTENT_BIN}"
 }
 
 persist_save() {
   [[ ${IPF_SKIP_PERSIST} == 1 ]] && return 0
-  persist_available || {
-    log_err '未找到 netfilter-persistent，无法保存规则。'
-    return 1
-  }
+  persist_available || { log_err '未找到 netfilter-persistent，无法保存规则。'; return 1; }
   "${NETFILTER_PERSISTENT_BIN}" save >/dev/null
 }
 
 persist_reload() {
   [[ ${IPF_SKIP_PERSIST} == 1 ]] && return 0
-  persist_available || {
-    log_err '未找到 netfilter-persistent，无法重载规则。'
-    return 1
-  }
+  persist_available || { log_err '未找到 netfilter-persistent，无法重载规则。'; return 1; }
   "${NETFILTER_PERSISTENT_BIN}" reload >/dev/null
 }