conf.c: Cleanup __S_ISTYPE
conf.c: Cleanup __S_ISTYPE

__S_ISTYPE doesn't exist in all C libraries, so define it if it's missing.
Additionaly, replace one occurence where it wasn't actually needed.

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>
Acked-by: Serge E. Hallyn <3df611b026e4639bee8aef7a4beb2e39fcebb313@ubuntu.com>

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