clk: qcom: smd-rpm: simplify locking with guard()

Simplify error handling (less gotos) over locks with guard().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240823-cleanup-h-guard-clk-qcom-v1-2-68bb9601c9dd@linaro.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>