Fixes this compiler warning:

drivers/media/pci/zoran/zoran_card.c: In function 'zoran_probe':
drivers/media/pci/zoran/zoran_card.c:1316:62: warning: '%u' directive output may be truncated writing between 1 and 5 bytes into a region of size between 0 and 31 [-Wformat-truncation=]
 1316 |         snprintf(ZR_DEVNAME(zr), sizeof(ZR_DEVNAME(zr)), "%s[%u]",
      |                                                              ^~
drivers/media/pci/zoran/zoran_card.c:1316:58: note: directive argument in the range [0, 65535]
 1316 |         snprintf(ZR_DEVNAME(zr), sizeof(ZR_DEVNAME(zr)), "%s[%u]",
      |                                                          ^~~~~~~~
drivers/media/pci/zoran/zoran_card.c:1316:9: note: 'snprintf' output between 4 and 39 bytes into a destination of size 32
 1316 |         snprintf(ZR_DEVNAME(zr), sizeof(ZR_DEVNAME(zr)), "%s[%u]",
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 1317 |                  zr->card.name, zr->id);
      |                  ~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>