No longer override the default kernel font if nothing is specified in
vconsole.conf.
The default kernel font[0] provides ISO-8859-1 and box characters. Users
of Arabic, Cyrilic or Hebrew must set a different font manually as these
character sets were provided by the old default font [1], but are not
any longer.
Rationale:
* it is counter-intuitive that an empty vconsole.conf file is different
from adding FONT="";
* the version of the default font shipped with Arch (which is the
upstream one) behaves very badly during early boot[2] (which should
admittedly be fixed in the font itself);
* the kernel already supplies a default font, it seems reasonable to
use that unless anything else is specified;
* This also avoids a needless slow call to setfont; and
* We don't want to work around problems in the kernel (in case the
compiled-in font is not acceptable for whatever reason).