USB: apple-mfi-fastcharge: fix reference leak in apple_mfi_fc_set_property

USB: apple-mfi-fastcharge: fix reference leak in apple_mfi_fc_set_property

pm_runtime_get_sync() will increment pm usage at first and it
will resume the device later. If runtime of the device has
error or device is in inaccessible state(or other error state),
resume operation will fail. If we do not call put operation to
decrease the reference, the result is that this device cannot
enter the idle state and always stay busy or other non-idle
state.

Fixes: 249fa8217b846 ("USB: Add driver to control USB fast charge for iOS devices")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201102022650.67115-1-zhangqilong3@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>