hw/misc/applesmc: Fix memory leak in reset() handler

hw/misc/applesmc: Fix memory leak in reset() handler

AppleSMCData is allocated with g_new0() in applesmc_add_key():
release it with g_free().

Leaked since commit 1ddda5cd36 ("AppleSMC device emulation").

Cc: qemu-stable@nongnu.org
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2272
Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20240408095217.57239-3-philmd@linaro.org>
(cherry picked from commit fc09ff2979defdcf8d00c2db94022d5d610e36ba)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>