Fix the error handling when pm_runtime_get_sync() fails.

If pm_runtime_get_sync() fails, call pm_runtime_disable() so there are no
unbalanced pm_runtime_enable() calls.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NJingoo Han <jingoohan1@gmail.com>