lshal: fix output streams for testing.

ListCommand does not keep a reference to output
and err streams (for easier mock in testing). Instead,
ListCommand uses out() and err() that calls into
Lshal::out() and err().

Test: lshal
Test: lshal_test
Change-Id: Ie6720833ad513ba5cb1246e34ef96afed5d4373c
3 files changed