hwmon: (aquacomputer_d5next) Fix length of speed_input array

Commit 120584c7 ("hwmon: (aquacomputer_d5next) Add support for Octo
flow sensor") added support for reading Octo flow sensor, but didn't
update the priv->speed_input array length. Since Octo has 8 fans, with
the addition of the flow sensor the proper length for speed_input is 9.

Reported by Arne Schwabe on Github [1], who received a UBSAN warning.

Fixes: 120584c7 ("hwmon: (aquacomputer_d5next) Add support for Octo flow sensor")
Closes: https://github.com/aleksamagicka/aquacomputer_d5next-hwmon/issues/100

 [1]
Reported-by: Arne Schwabe <arne@rfc2549.org>
Signed-off-by: Aleksa Savic <savicaleksa83@gmail.com>
Message-ID: <20241124152725.7205-1-savicaleksa83@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>