nplab-*test: Fix printing of junit on stdout
Before this patch the printing of the junit.xml to stdout fails:
+ collect_logs
+ cat '/tmp/tmp.CzafJpQyw8/*/junit-*.log'
cat: '/tmp/tmp.CzafJpQyw8/*/junit-*.log': No such file or directory
+ true
Change-Id: I600d3bdb3de23ef6f381cd5b81e2b851856b2b9b
