usb: fotg210-hcd: Fix an error message

'retval' is known to be -ENODEV here.
This is a hard-coded default error code which is not useful in the error
message. Moreover, another error message is printed at the end of the
error handling path. The corresponding error code (-ENOMEM) is more
informative.

So remove simplify the first error message.

While at it, also remove the useless initialization of 'retval'.

Fixes: 7d50195f

 ("usb: host: Faraday fotg210-hcd driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/94531bcff98e46d4f9c20183a90b7f47f699126c.1620333419.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>