conf: add lxc_wants_cap() helper

src/lxc/cgroups/cgfsng.c

@@ -1831,10 +1831,7 @@ __cgfsng_ops static bool cgfsng_mount(struct cgroup_ops *ops,
 	}
 
 	if (!wants_force_mount) {
-		if (!lxc_list_empty(&handler->conf->keepcaps))
-			wants_force_mount = !in_caplist(CAP_SYS_ADMIN, &handler->conf->keepcaps);
-		else
-			wants_force_mount = in_caplist(CAP_SYS_ADMIN, &handler->conf->caps);
+		wants_force_mount = lxc_wants_cap(CAP_SYS_ADMIN, handler->conf);
 
 		/*
 		 * Most recent distro versions currently have init system that

src/lxc/conf.h

@@ -501,6 +501,15 @@ __hidden extern int run_script(const char *name, const char *section, const char
 __hidden extern int run_script_argv(const char *name, unsigned int hook_version, const char *section,
 				    const char *script, const char *hookname, char **argsin);
 __hidden extern int in_caplist(int cap, struct lxc_list *caps);
+
+static inline int lxc_wants_cap(int cap, struct lxc_conf *conf)
+{
+	if (!lxc_list_empty(&conf->keepcaps))
+		return !in_caplist(cap, &conf->keepcaps);
+
+	return in_caplist(cap, &conf->caps);
+}
+
 __hidden extern int setup_sysctl_parameters(struct lxc_list *sysctls);
 __hidden extern int lxc_clear_sysctls(struct lxc_conf *c, const char *key);
 __hidden extern int setup_proc_filesystem(struct lxc_list *procs, pid_t pid);