[ALSA] pcxhr - Fix printk warning

Modules: Digigram PCXHR driver

sound/pci/pcxhr/pcxhr.c: In function 'pcxhr_update_r_buffer':
sound/pci/pcxhr/pcxhr.c:460: warning: unsigned int format, different type arg (arg 7)

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>