usb: gadged: pch_udc: get rid of redundant assignments

It seems there are leftovers of some assignments which are not used
anymore.  Compiler even warns us about:

drivers/usb/gadget/udc/pch_udc.c:2022:22: warning: variable ‘dev’ set \
but not used [-Wunused-but-set-variable]

drivers/usb/gadget/udc/pch_udc.c:2639:9: warning: variable ‘ret’ set \
but not used [-Wunused-but-set-variable]

Remove them and shut compiler about.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>