Fix a few uninitialized error checks that were introduced recently
mistakenlly during the clean-up:
  sound/pci/ctxfi/ctamixer.c: In function ‘get_amixer_rsc’:
  sound/pci/ctxfi/ctamixer.c:261: warning: ‘err’ may be used uninitialized in this function
  sound/pci/ctxfi/ctamixer.c: In function ‘get_sum_rsc’:
  sound/pci/ctxfi/ctamixer.c:415: warning: ‘err’ may be used uninitialized in this function
  sound/pci/ctxfi/ctsrc.c: In function ‘get_srcimp_rsc’:
  sound/pci/ctxfi/ctsrc.c:742: warning: ‘err’ may be used uninitialized in this function
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Remove useless variable initializations and cast at the beginning of
functions.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Added ctxfi: prefix to each debug print.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The Sound Blaster X-Fi driver supports Creative solutions based on
20K1 and 20K2 chipsets.

Supported hardware :

Creative Sound Blaster X-Fi Titanium Fatal1ty® Champion Series
Creative Sound Blaster X-Fi Titanium Fatal1ty Professional Series
Creative Sound Blaster X-Fi Titanium Professional Audio
Creative Sound Blaster X-Fi Titanium
Creative Sound Blaster X-Fi Elite Pro
Creative Sound Blaster X-Fi Platinum
Creative Sound Blaster X-Fi Fatal1ty
Creative Sound Blaster X-Fi XtremeGamer
Creative Sound Blaster X-Fi XtremeMusic

Current release features:

* ALSA PCM Playback
* ALSA Record
* ALSA Mixer

Note:

* External I/O modules detection not included.
Signed-off-by: NWai Yew CHAY <wychay@ctl.creative.com>
Singed-off-by: NRyan RICHARDS <ryan_richards@creativelabs.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>