target/sparc: use signed denominator in sdiv helper

target/sparc: use signed denominator in sdiv helper

The result has to be done with the signed denominator (b32) instead of
the unsigned value passed in argument (b).

Cc: qemu-stable@nongnu.org
Fixes: 1326010322d6 ("target/sparc: Remove CC_OP_DIV")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2319
Signed-off-by: Clément Chigot <chigot@adacore.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240606144331.698361-1-chigot@adacore.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>