PM: AVS: qcom-cpr: simplify the return expression of cpr_disable()

Simplify the return expression.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Kevin Hilman <khilman@baylibre.com>
[ rjw: Minor subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>