usb: dwc3: gadget: Fix runtime PM vote from pull_up handler

If gadget driver's request for removing pull_up fails due to
EP0 not in setup phase, then driver ends up bailing out
without removing it PM usage_count vote.
This will prevent DWC3 from entering low power mode and
subsequent start_peripheral/host would also won't be
allowed as LPM entry is mandatory for that.

Change-Id: Id1dde0dcf379a1f6b9567d63c0b1d31445c30d0d
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>