ALSA: seq: Fix yet another spot for system message conversion

We fixed the incorrect UMP type for system messages in the recent
commit, but it missed one place in system_ev_to_ump_midi1().
Fix it now.

Fixes: e9e02819

 ("ALSA: seq: Automatic conversion of UMP events")
Fixes: c2bb79613fed ("ALSA: seq: Fix incorrect UMP type for system messages")
Link: https://lore.kernel.org/r/20240530101044.17524-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>