lshal: fix file streams for testing.

* If a file is specified for list, the file is opened and
  closed within the ListCommand::dump() function.

* Add a missing break in ListCommand::parseArgs, case
  for '--init-vintf'

Test: lshal_test
Test: lshal --init-vintf
Test: lshal --init-vintf=/data/data/a.xml ; adb shell cat \
      /data/data/a.xml
Test: lshal -d
Test: lshal --debug=/data/data/d.txt ; adb shell cat \
      /data/data/d.txt

Change-Id: I1acee5878638d25257a13244713dc416e9d8d6b2