qr: print_oops: implement scaling

Allow the scaling of QR codes by the qr_oops kernel parameter.
Also, implement safe guard against those who try a scale which
wouldn't fit on screen.

Signed-off-by: Levente Kurusa <levex@linux.com>
Merge pull request #4 from levex/for-teodora

Implement scaling of QR codes
qr: bitstream: use a more widely accepted allocation scheme

Signed-off-by: Levente Kurusa <levex@linux.com>
qr: bitstream: use ERR_PTR et al interface for errors

Signed-off-by: Levente Kurusa <levex@linux.com>