can: xilinx_can: handle failure cases of pm_runtime_get_sync

Calling pm_runtime_get_sync increments the counter even in case of
failure, causing incorrect ref count. Call pm_runtime_put if
pm_runtime_get_sync fails.

Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Link: https://lore.kernel.org/r/20200605033239.60664-1-navid.emamdoost@gmail.com


Fixes: 4716620d ("can: xilinx: Convert to runtime_pm")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>