usbnet_generic_cdc_bind() is duplicating the error handling
multiple times. That is bad. Unify it with jumps.

I find such a change description improvable another bit.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n659

V2: Update error logging with every cause a unique message

Please move patch version descriptions behind the marker line.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v7.0-rc3#n785

Regards,
Markus