lxc-netstat: improve finding fs mountpoint of hierarchy
lxc-netstat: improve finding fs mountpoint of hierarchy

We cannot assume that the mount source name always starts with 'cgroup'
so we check the filesystem type instead.

Use 'awk' instead of 'grep -E' and  as it is a better tool for this job.

This fixes the tool on systems using openrc.

Signed-off-by: Natanael Copa <d6dfbe96822fc6f407d114112670f8d1571509f1@alpinelinux.org>
Acked-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

smoser/lxc,hkjolhede/lxc,DarknessBeforeDawn/lxc,fwilson42/lxc,szaszg/lxc,Pelagicore/lxc,ysbnim/lxc,LynxChaus/lxc,hkjolhede/lxc,armcc/lxc,hallyn/lxc,aeris/lxc,regit/lxc,christiaan/lxc,yubo/lxc,major/lxc,smoser/lxc,Ponce/lxc,terceiro/lxc,rldleblanc/lxc,cjwatson/lxc,raspberrypython/lxc,efiop/lxc,JohnPeacockMessageSystems/lxc,smoser/lxc,smoser/lxc,federicobriata/lxc,cjwatson/lxc,sapun/lxc,GreatFruitOmsk/lxc,ksperis/lxc,regit/lxc,ojkastl/lxc_Patches,codebauss/lxc,ioops/lxc,jirislaby/lxc,ysbnim/lxc,virajs/lxc,caglar10ur/lxc,ss1h2a3tw/lxc,abstrakraft/lxc-android-lxc,JohnPeacockMessageSystems/lxc,hfuCN/lxc,sapun/lxc,bostjan/lxc,glensc/lxc,tych0/lxc,rowhit/lxc,christiaan/lxc,szaszg/lxc,raspberrypython/lxc,virajs/lxc,thmo/lxc,ss1h2a3tw/lxc,caglar10ur/lxc,ojkastl/lxc_Patches,lisongmin/lxc,GreatFruitOmsk/lxc,major/lxc,Pelagicore/lxc,major/lxc,akshaykarle/lxc,Ponce/lxc,QingweiPeterLan/cs188-lxc,aeris/lxc,ecarrara/lxc,lazy404/lxc,lazy404/lxc,jirislaby/lxc,codebauss/lxc,QingweiPeterLan/cs188-lxc,Distrotech/lxc,rldleblanc/lxc,federicobriata/lxc,rldleblanc/lxc,caglar10ur/lxc,fwilson42/lxc,ojkastl/lxc_Patches,glensc/lxc,bostjan/lxc,GreatFruitOmsk/lxc,tych0/lxc,aeris/lxc,ksperis/lxc,bmoar/lxc,bmoar/lxc,szaszg/lxc,hallyn/lxc,armcc/lxc,armcc/lxc,bostjan/lxc,raspberrypython/lxc,Distrotech/lxc,LynxChaus/lxc,fwilson42/lxc,christiaan/lxc,terceiro/lxc,DarknessBeforeDawn/lxc,Ponce/lxc,abstrakraft/lxc-android-lxc,Distrotech/lxc,yubo/lxc,ksperis/lxc,akshaykarle/lxc,hkjolhede/lxc,akshaykarle/lxc,glensc/lxc,lazy404/lxc,ss1h2a3tw/lxc,ioops/lxc,LynxChaus/lxc,QingweiPeterLan/cs188-lxc,virajs/lxc,abstrakraft/lxc-android-lxc,hfuCN/lxc,weizhenwei/lxc,codebauss/lxc,DarknessBeforeDawn/lxc,rowhit/lxc,thmo/lxc,hallyn/lxc,rowhit/lxc,abstrakraft/lxc-android-lxc,lisongmin/lxc,efiop/lxc,ysbnim/lxc,weizhenwei/lxc,hfuCN/lxc,efiop/lxc,ojkastl/lxc_Patches,JohnPeacockMessageSystems/lxc,regit/lxc,ecarrara/lxc,thmo/lxc,bmoar/lxc,lisongmin/lxc,Pelagicore/lxc,cjwatson/lxc,ioops/lxc,jirislaby/lxc,federicobriata/lxc,weizhenwei/lxc,ecarrara/lxc,terceiro/lxc,sapun/lxc,tych0/lxc,yubo/lxc