[ALSA] sound: pcxhr_core.c fix shadowed variable warning

Inner loop redeclares err with u32 rather than int, stupid fix here
is to change the inner err to err2.
sound/pci/pcxhr/pcxhr_core.c:1008:8: warning: symbol 'err' shadows an earlier one
sound/pci/pcxhr/pcxhr_core.c:983:6: originally declared here

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>