inittab: fallback when multiple "console=" is detected

inittab: fallback when multiple "console=" is detected

Linux Kernel uses a console in the last "console=" parameter in bootargs
as /dev/console, so falllback to /dev/console or get_active_console()
when multiple "console=" parameter is found in bootargs, instead of
using the first console.

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>