dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()

pm_runtime_get_sync will increment pm usage counter even it failed.
Forgetting to putting operation will result in reference leak here.
Fix it by moving the error_pm label above the pm_runtime_put() in
the error path.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20210706124521.1371901-1-yukuai3@huawei.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>