usb: gadget: fsl_udc_core: fixup struct_udc_setup documentation

The original implementation from commit b504882da539
("USB: add Freescale high-speed USB SOC device controller driver")
returned NULL on failure and an allocated + initialized struct fsl_udc on
success. The current code introduced in commit 4365831dadfe
("USB: fsl_usb2_udc: Get max ep number from DCCPARAMS register") only
provides partial initialization as well as returning 0 on success and -1
on failures. The function documentation is updated accordingly.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: 4365831dadfe ("USB: fsl_usb2_udc: Get max ep number from DCCPARAMS register")
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/fsl_udc_core.c

@@ -2234,8 +2234,10 @@ static void fsl_udc_release(struct device *dev)
 	Internal structure setup functions
 *******************************************************************/
 /*------------------------------------------------------------------
- * init resource for globle controller
- * Return the udc handle on success or NULL on failure
+ * init resource for global controller called by fsl_udc_probe()
+ * On success the udc handle is initialized, on failure it is
+ * unchanged (reset).
+ * Return 0 on success and -1 on allocation failure
  ------------------------------------------------------------------*/
 static int struct_udc_setup(struct fsl_udc *udc,
 		struct platform_device *pdev)