The previous patch to allow the hwspinlock code to be disabled missed
handling the free in the error path, do so using the better IS_ENABLED()
pattern as suggested by Baolin. While we're at it also check that we have
a hardware spinlock before freeing it - the core code reports an error
when freeing an invalid lock.
Suggested-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>