make_keyblock: change to parsing key prefix

Instead of requiring an arg, just check if the private key starts with
"remote:" to detect omitting the extension.

BUG=b:318522770
BRANCH=None
TEST=[None|unit-test|led-launch]

Change-Id: I55f04e25a43b2e9fe3ddf3951e48b29a6fe26d49
Signed-off-by: Benjamin Shai <bshai@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/5201825
Reviewed-by: George Engelbrecht <engeg@google.com>
Commit-Queue: Julius Werner <jwerner@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
1 file changed