login: Add quote around disk serial number

A serial number may contain space. Add quote to ensure the serial number is
properly interpreted.

BUG=chromium:765962
TEST=Check in /run/session_manager/machine-info that serial numbers have quotes.
Check session_manager reports the full disk serial name.
Note that without quotes session_manager is interpreting the variable properly,
so this CL is a NOP feature-wise.

Change-Id: I848c3d6484ce9510c3d03334a316968732824a6e
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/706148
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 25013c07881a4039929997e939fe033676a2f284)
Reviewed-on: https://chromium-review.googlesource.com/716556
2 files changed