Check /dev/console using init_stat()

vfs_lstat() which was used previously would fail with certain
configurations. This was likely due to the involved functions being
marked __init at some point in the past.

Signed-off-by: Sven Schwermer <sven.schwermer@disruptive-technologies.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>