ALSA: echoaudio: add reference of struct echoaudio

added reference of struct echoaudio to free_firmware function.
this structure will be later used to get a reference of the card
when converting snd_printk to dev_* in the next patch of the series.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
ALSA: echoaudio: remove all snd_printk

removed all references of snd_printk with the standard dev_* macro.

[a few places degraded to dev_dbg(), too -- tiwai]

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
ALSA: emu10k1: Deletion of unnecessary checks before three function calls

The functions kfree(), release_firmware() and snd_util_memhdr_free() test
whether their argument is NULL and then return immediately. Thus the test
around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>