ALSA: wavefront: remove redundant assignment to pointer end

ALSA: wavefront: remove redundant assignment to pointer end

Pointer end is being re-assigned the same value as it was initialized
with in the previous statement. The re-assignment is redundant and
can be removed.

Cleans up clang scan-build warning:
sound/isa/wavefront/wavefront_synth.c:582:17: warning: Value stored
to 'end' during its initialization is never read

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220629102744.139673-1-colin.i.king@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>