Fixed nn_device shutdown on Windows
Fixed nn_device shutdown on Windows

Signed-off-by: Martin Sustrik <4dd6061be1198639e8b05ce4fd5ead7a0dcaa0f4@250bpm.com>

thisco-de/nanomsg,pch957/nanomsg,TTimo/nanomsg,kaostao/nanomsg,potatogim/nanomsg,potatogim/nanomsg,imp/nanomsg,JackDunaway/featherweight-nanomsg,cosin2008/nanomsg.NET,simplestbest/nanomsg,hyperfact/nanomsg,smithed/nanomsg,yan97ao/nanomsg,gdamore/mamomsg,linearregression/nanomsg,nirs/nanomsg,ttyangf/nanomsg,zerotacg/nanomsg,TTimo/nanomsg,nirs/nanomsg,tempbottle/nanomsg,featherweight/ftw-kernel-nanomsg,krafczyk/nanomsg,kaostao/nanomsg,kaostao/nanomsg,pakozm/nanomsg,JackDunaway/featherweight-nanomsg,cosin2008/nanomsg.NET,pakozm/nanomsg,snikulov/nanomsg,nirs/nanomsg,tempbottle/nanomsg,wfxiang08/nanomsg,linearregression/nanomsg,pch957/nanomsg,reqshark/nanomsg,smithed/nanomsg,cosin2008/nanomsg.NET,modulexcite/nanomsg,wirebirdlabs/featherweight-nanomsg,krafczyk/nanomsg,linearregression/nanomsg,imp/nanomsg,krafczyk/nanomsg,wfxiang08/nanomsg,pch957/nanomsg,yan97ao/nanomsg,kaostao/nanomsg,imp/nanomsg,JackDunaway/featherweight-nanomsg,reqshark/nanomsg,ttyangf/nanomsg,modulexcite/nanomsg,hyperfact/nanomsg,zerotacg/nanomsg,simplestbest/nanomsg,featherweight/ftw-kernel-nanomsg,reqshark/nanomsg,TTimo/nanomsg,modulexcite/nanomsg,snikulov/nanomsg,simplestbest/nanomsg,potatogim/nanomsg,TTimo/nanomsg,wirebirdlabs/featherweight-nanomsg,smithed/nanomsg,yan97ao/nanomsg,wfxiang08/nanomsg,zerotacg/nanomsg,ttyangf/nanomsg,gdamore/mamomsg,smithed/nanomsg,pakozm/nanomsg,ttyangf/nanomsg,wirebirdlabs/featherweight-nanomsg,gdamore/mamomsg,hyperfact/nanomsg,tempbottle/nanomsg,thisco-de/nanomsg