cpufreq: qcom: fix memory leak in error path

If for some reason the speedbin length is incorrect, then there is a
memory leak in the error path because we never free the speedbin buffer.
This commit fixes the error path to always free the speedbin buffer.

Cc: v5.7+ <stable@vger.kernel.org> # v5.7+
Fixes: a8811ec7 ("cpufreq: qcom: Add support for krait based socs")
Signed-off-by: Fabien Parent <fabien.parent@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>