usb: gadget: core: remove unbalanced mutex_unlock in usb_gadget_activate

usb: gadget: core: remove unbalanced mutex_unlock in usb_gadget_activate

Commit 286d9975a838 ("usb: gadget: udc: core: Prevent soft_connect_store() race")
introduced one extra mutex_unlock of connect_lock in the usb_gadget_active function.

Fixes: 286d9975a838 ("usb: gadget: udc: core: Prevent soft_connect_store() race")
Cc: stable <stable@kernel.org>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20230721222256.1743645-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>