minidiag/ui: Prevent calling update action if memory test is finished

Skip calling diagnostics_memory_update_screen() action if memory test is
finished to reduce delays in memory diagnostics screens.

BUG=b:168776970, b:171852478
BRANCH=none
TEST=Build locally, boot recovery, select 'run diagnostics',
     enter memory test (quick) screen, wait until test is finished,
     and observe that the delay reduces while pressing keyboard

Signed-off-by: Hsuan Ting Chen <roccochen@chromium.org>
Change-Id: I4f8dbadc68989112bce418119ff7405ec150a7df
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/2423089
2 files changed