hwmon: (hs3001) remove redundant store on division

Currently the local variable hum is being divided by a constant and
the results is being re-assigned back to hum before the value is being
returned to the caller. The assignment to hum is redundant and can
be removed.

Cleans up clang scan build warning:
drivers/hwmon/hs3001.c:65:9: warning: Although the value stored to 'hum'
is used in the enclosing expression, the value is never actually read
from 'hum' [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20231023135828.667297-1-colin.i.king@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>