usb: dwc3: qcom: Add missing DWC3 OF node refcount decrement

usb: dwc3: qcom: Add missing DWC3 OF node refcount decrement

of_get_child_by_name() increments the reference counter of the OF node it
managed to find. So after the code is done using the device node, the
refcount must be decremented. Add missing of_node_put() invocation then
to the dwc3_qcom_of_register_core() method, since DWC3 OF node is being
used only there.

Fixes: a4333c3a6ba9 ("usb: dwc3: Add Qualcomm DWC3 glue driver")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20210212205521.14280-1-Sergey.Semin@baikalelectronics.ru
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>