lib: sbi: sse: simplify 32bits overflow check

Rather than checking 32bits overflow with some absolute value, check the
value to be different from the cast itself.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reported-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>