vc_translate is used only in vt.c, so move the definition from a header
there. Also, it used to be a macro, so be modern and make a static
inline from it. This makes the code actually readable.

And as a preparation for next patches, rename it to vc_translate_ascii.
vc_translate will be a wrapper for both unicode and this one.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-10-jslaby@suse.czSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>