ALSA: ump: Drop redundant check of note-on with zero velocity

The check of a note-on event with zero velocity is done twice, and the
latter one is superfluous.  Let's drop it.

Fixes: 0b5288f5

 ("ALSA: ump: Add legacy raw MIDI support")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/4683198a-84f6-4238-9e87-c70667d84523@kili.mountain


Suggested-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20230525083124.15277-1-tiwai@suse.de


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