tty/vt: consolemap: make parameters of inverse_translate() saner

tty/vt: consolemap: make parameters of inverse_translate() saner

- int use_unicode -> bool: it's used as bool at some places already, so
  make it explicit.
- int glyph -> u16: every caller passes a u16 in. So make it explicit
  too. And remove a negative check from inverse_translate() as it never
  could be negative.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>