setconsole: much better help text

setconsole: much better help text

Was:

    Usage: setconsole [-r] [DEVICE]

    Redirect system console output to DEVICE (default: /dev/tty)

        -r	Reset output to /dev/console

Now:

    Usage: setconsole [-r] [DEVICE]

    Make writes to /dev/console appear on DEVICE (default: /dev/tty).
    Does not redirect kernel log output or reads from /dev/console.

        -r	Reset: writes to /dev/console go to kernel log tty(s)

function                                             old     new   delta
packed_usage                                       31766   31777     +11
setconsole_main                                       84      78      -6

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>