ALSA: ua101: fix division by zero at probe

Add the missing endpoint max-packet sanity check to probe() to avoid
division by zero in alloc_stream_buffers() in case a malicious device
has broken descriptors (or when doing descriptor fuzz testing).

Note that USB core will reject URBs submitted for endpoints with zero
wMaxPacketSize but that drivers doing packet-size calculations still
need to handle this (cf. commit 2548288b ("USB: Fix: Don't skip
endpoint descriptors with maxpacket=0")).

Fixes: 63978ab3 ("sound: add Edirol UA-101 support")
Cc: stable@vger.kernel.org      # 2.6.34
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211026095401.26522-1-johan@kernel.org


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