block, bfq: update Paolo's address in maintainer list

Current email address of Paolo Valente is no longer valid, use a good one.

Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Link: https://lore.kernel.org/r/20230523091724.26636-1-paolo.valente@unimore.it
Signed-off-by: Jens Axboe <axboe@kernel.dk>