USB: OHCI: remove bogus #error

The OHCI host controller driver can be built standalone now,
without enabling any of the available bus glue drivers, so
there is not really a reason to error out here:

drivers/usb/host/ohci-hcd.c:1258: error:
 #error "missing bus glue for ohci-hcd"  #error "missing bus glue for ohci-hcd"

This follows the same change done in ehci recently as 843e56c0
"USB: EHCI: remove bogus #error" and hopefully avoids future
merge conflicts in this list.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>