Simplify lua_cmsgpack macro and fix build on old Linux distros.
Simplify lua_cmsgpack macro and fix build on old Linux distros.

Thanks to @badboy for the help in checking the build after the fix.

louisliangjun/redis,xuzhezhaozhao/redis_reading,splitice/redis,MSOpenTech/redis,xuzhezhaozhao/redis_reading,jxwr/redis,darksideofthemoo/redis-histogram,MSOpenTech/redis,maodeyi/redis_lua,splitice/redis,maodeyi/redis_lua,HunanTV/redis,ksarch-saas/redis,jxwr/redis,xuzhezhaozhao/redis_reading,himoca/redis,ttuna/msot-redis,slfs007/mk-redis,spearhead-ea/redis,HunanTV/redis,maodeyi/redis_lua,ksarch-saas/redis,himoca/redis,louisliangjun/redis,splitice/redis,MSOpenTech/redis,spearhead-ea/redis,xuzhezhaozhao/redis_reading,MSOpenTech/redis,ttuna/msot-redis,ramonsnir/redis,ramonsnir/redis,darksideofthemoo/redis-histogram,HunanTV/redis,ttuna/msot-redis,darksideofthemoo/redis-histogram,jxwr/redis,splitice/redis,ksarch-saas/redis,slfs007/mk-redis,louisliangjun/redis,darksideofthemoo/redis-histogram,louisliangjun/redis,himoca/redis,slfs007/mk-redis,ksarch-saas/redis,MSOpenTech/redis,HunanTV/redis,ramonsnir/redis,ttuna/msot-redis,ttuna/msot-redis,spearhead-ea/redis