USB: Allow initialization of broken keyspan serial adapters.

Fixes the keyspan driver after the addition of additional
checking of driver requirements introduced in usb-serial.c
commit 063a2da8

.  The initialization
of the keyspan usb_serial_driver structs were not initializing the
num_interrupt_out field and the additional checking was rejecting
the end point so the driver wouldn't finish initializing.

This commit initializes the fields to NUM_DONT_CARE.
It works for the keyspan USA-49WG and doesn't break the USA-19HS
which are the two keyspan devices I have to test with.

Signed-off-by: Clark Rawlins <clark.rawlins@escient.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>