net: withNetNS: attempt to revert net ns in case of error
net: withNetNS: attempt to revert net ns in case of error

Before this patch, when withNetNS() returns with an error, the current
net namespace is undefined. In order to make the API more readable,
withNetNS() should always at least attempt to return in a defined
namespace used before being called, even in case of errors.

In practice, the only caller of withNetNS will handle the error case
correctly by calling Teardown() so there should be no functional changes
with this patch.

s-urbaniak/rkt,alexhersh/rkt,coreos/rkt,adfernandes/rkt,bsmr-go/rkt,chrisseto/rkt,chrisseto/rkt,mattthias/pkg-rkt,MattDees/rkt,shobhit85/rkt,ChengTiesheng/rkt,rhvgoyal/rkt,lucasallan/rkt,lsm5/rkt,ramitsurana05/rkt,il9ue/rkt,euank/rkt,robszumski/rocket,smarvin/rkt,yifan-gu/rocket,matthaias/rkt,monstermunchkin/rkt,intfrr/rkt,ramitsurana05/rkt,tixxdz/rkt,alban/rkt,alexhersh/rkt,akshaykarle/rkt,squeed/rkt,matthaias/rkt,kbrwn/rkt,jjlakis/rkt,linki/rkt,il9ue/rkt,cab105/rkt,lucasallan/rkt,s-urbaniak/rkt,endocode/rkt,Wilybald/rkt,marineam/rkt,michelangelo13/rkt,luebken/rkt,michelangelo13/rkt,Shashwatsh/rkt,rot26/rkt,endocode/rkt,kbrwn/rkt,squaremo/rkt,linki/rkt,crawford/rkt,alban/rkt,monstermunchkin/rkt,mjg59/rkt,lucasallan/rkt,xnox/rkt,jjlakis/rkt,Wilybald/rkt,s-urbaniak/rkt,wparad/rkt,linki/rkt,markllama/rkt,euank/rkt,yifan-gu/rkt,klizhentas/rkt,monstermunchkin/rkt,ramitsurana/rkt,yifan-gu/rkt,akshaykarle/rkt,sstabellini/rkt,liugenping/rkt,intfrr/rkt,tv42/rkt,blixtra/rkt,smarvin/rkt,tmrts/rkt,coreos/rkt,fdserr/rkt,wparad/rkt,nhlfr/rkt,dgonyeo/rkt,mattthias/pkg-rkt,adfernandes/rkt,iankronquist/rkt,iaguis/rkt,rot26/rkt,mattthias/pkg-rkt,clearlinux/rkt,bsmr-go/rkt,sgotti/rkt,marineam/rkt,marineam/rkt,shtouff/rkt,luebken/rkt,crawford/rkt,rhvgoyal/rkt,krnowak/rkt,Yhgenomics/rkt,sinfomicien/rkt,ramitsurana05/rkt,blixtra/rkt,wparad/rkt,Shashwatsh/rkt,MabinGo/rkt,tmrts/rkt,dalanlan/rkt,iaguis/rkt,liubq919/rkt,sstabellini/rkt,liubq919/rkt,kinvolk/rkt,clearlinux/rkt,jakon89/rkt,rot26/rkt,krnowak/rkt,kinvolk/rkt,rkt/rkt,squeed/rkt,jonboulle/rkt,alexhersh/rkt,xnox/rkt,michelangelo13/rkt,robszumski/rocket,cab105/rkt,bsmr-go/rkt,rkt/rkt,mike1729/rkt,iaguis/rkt,luebken/rkt,joshix/rkt,jonboulle/rkt,mike1729/rkt,Shashwatsh/rkt,krnowak/rkt,lee212/rkt,intfrr/rkt,ybubnov/rkt,lsm5/rkt,lee212/rkt,chrisseto/rkt,liugenping/rkt,ramitsurana/rkt,jakon89/rkt,jzelinskie/rkt,jjlakis/rkt,sinfomicien/rkt,ybubnov/rkt,fdserr/rkt,matthaias/rkt,crawford/rkt,rkt/rkt,il9ue/rkt,nhlfr/rkt,cab105/rkt,MattDees/rkt,liugenping/rkt,klizhentas/rkt,Wilybald/rkt,rhvgoyal/rkt,endocode/rkt,joshix/rkt,dgonyeo/rkt,rkt/rkt,kbrwn/rkt,maquanyi/rkt,dalanlan/rkt,lucasallan/rkt,ChengTiesheng/rkt,ramitsurana/rkt,Yhgenomics/rkt,markllama/rkt,intelsdi-x/rkt,jzelinskie/rkt,achanda/rkt,ChengTiesheng/rkt,mike1729/rkt,mjg59/rkt,jasonchaffee/rkt,MattDees/rkt,tixxdz/rkt,shtouff/rkt,MabinGo/rkt,yifan-gu/rocket,lsm5/rkt,achanda/rkt,sgotti/rkt,jonboulle/rkt,intelsdi-x/rkt,kinvolk/rkt,dalanlan/rkt,squaremo/rkt,klizhentas/rkt,squaremo/rkt,jzelinskie/rkt,akshaykarle/rkt,tmrts/rkt,sstabellini/rkt,intelsdi-x/rkt,shtouff/rkt,yifan-gu/rkt,sgotti/rkt,maquanyi/rkt,tixxdz/rkt,shobhit85/rkt,mjg59/rkt,yifan-gu/rocket,shobhit85/rkt,fdserr/rkt,joshix/rkt,jasonchaffee/rkt,dgonyeo/rkt,jakon89/rkt,alban/rkt,xnox/rkt,clearlinux/rkt,tv42/rkt,jasonchaffee/rkt,kinvolk/rkt,coreos/rkt,squeed/rkt,achanda/rkt,joshix/rkt,ybubnov/rkt,blixtra/rkt,smarvin/rkt,euank/rkt,lee212/rkt,iankronquist/rkt,maquanyi/rkt,MabinGo/rkt,Wilybald/rkt,nhlfr/rkt,tv42/rkt,robszumski/rocket,sinfomicien/rkt,liubq919/rkt,adfernandes/rkt,Yhgenomics/rkt,markllama/rkt,iankronquist/rkt