This patch corrects the below locking imbalance warnings:
drivers/usb/dwc_otg_310/dwc_otg_driver.c:406 dwc_otg_force_device()
warn: inconsistent returns 'irqsave:flags'.
Locked on: line 390
Unlocked on: line 406
Change-Id: Id79ebe0d41fbbab38c59384e23d7e2133c436c96 Signed-off-by: Frank Wang <frank.wang@rock-chips.com>