USB: fix ohci.h over-use warnings

When u132-hcd is built, it includes local header ohci.h, which appears
to have been intended only for use by ohci-hcd.

This throws warnings about functions which are defined and not used.
The warnings thrown are because three small functions are implemented in
the header, but not declared 'inline', a rather strange affair.

Since these functions are small, let's go ahead and define them as
'inline', just like the inline functions surrounding them.  This makes
things more consistent, and kills the warnings.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>