media: dib7000m: incorrect format specifier detected by clang

drivers/media/dvb-frontends/dib7000m.c:811:38: warning: format specifies type 'short' but the argument has type 'u8' (aka 'unsigned char') [-Wformat]
                        dprintk("SPLIT %p: %hd\n", demod, agc_split);
                                           ~~~            ^~~~~~~~~
                                           %hhu

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>