ALSA: echoaudio: remove unused variable

This patch cleans up the code in the __snd_echo_probe function of the
echoaudio.c driver by removing the unused variable i and moving the
declaration of the loop variable i inside the foor loops where it is
used

Signed-off-by: Andres Urian Florez <andres.emb.sys@gmail.com>
Link: https://patch.msgid.link/20250319020515.22150-1-andres.emb.sys@gmail.com


Signed-off-by: Takashi Iwai <tiwai@suse.de>