vt: ioctl, switch VT_IS_IN_USE and VT_BUSY to inlines

commit e587e8f17433ddb26954f0edf5b2f95c42155ae9 upstream.

These two were macros. Switch them to static inlines, so that it's more
understandable what they are doing.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219073951.16151-2-jslaby@suse.cz


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>