More error checking in package_etw.bat
More error checking in package_etw.bat

ariccio/UIforETW,ariccio/UIforETW,mwinterb/UIforETW,google/UIforETW,ariccio/UIforETW,mwinterb/UIforETW,google/UIforETW,google/UIforETW,MikeMarcin/UIforETW,google/UIforETW,MikeMarcin/UIforETW,ariccio/UIforETW,mwinterb/UIforETW,MikeMarcin/UIforETW