usb: gadget: bcm63xx_udc: Use common error handling code in bcm63xx_udc_probe()

Add a jump target so that a specific error message is stored only once
at the end of this function implementation.
Replace two calls of the function "dev_err" by goto statements.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>