USB: cdc-acm: use define for timeout

We have a symbolic name for the standard timeout.
Use it. No functional change intended.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20220629132638.31810-1-oneukum@suse.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>