usb: cdns3: Don't use priv_dev uninitialized in cdns3_gadget_ep_enable()

usb: cdns3: Don't use priv_dev uninitialized in cdns3_gadget_ep_enable()

Clang warns:

  drivers/usb/cdns3/cdns3-gadget.c:2290:11: error: variable 'priv_dev' is uninitialized when used here [-Werror,-Wuninitialized]
                  dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
                          ^~~~~~~~
  include/linux/dev_printk.h:155:18: note: expanded from macro 'dev_dbg'
          dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
                          ^~~
  include/linux/dynamic_debug.h:167:7: note: expanded from macro 'dynamic_dev_dbg'
                          dev, fmt, ##__VA_ARGS__)
                          ^~~
  include/linux/dynamic_debug.h:152:56: note: expanded from macro '_dynamic_func_call'
          __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
                                                              ^~~~~~~~~~~
  include/linux/dynamic_debug.h:134:15: note: expanded from macro '__dynamic_func_call'
                  func(&id, ##__VA_ARGS__);               \
                              ^~~~~~~~~~~
  drivers/usb/cdns3/cdns3-gadget.c:2278:31: note: initialize the variable 'priv_dev' to silence this warning
          struct cdns3_device *priv_dev;
                                      ^
                                      = NULL
  1 error generated.

The priv_dev assignment was moved below the if statement to avoid
potentially dereferencing ep before it was checked but priv_dev is used
in the dev_dbg() call.

To fix this, move the priv_dev and comp_desc assignments back to their
original spot and hoist the ep check above those assignments with a call
to pr_debug() instead of dev_dbg().

Fixes: 6ba7eb0fda92 ("usb: cdns3: change place of 'priv_ep' assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable()")
Link: https://github.com/ClangBuiltLinux/linux/issues/1680
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>