IB/ipath: Fix WC format drift between user and kernel space

The kernel ib_wc structure now uses a QP pointer, but the user space
equivalent uses a QP number instead.  This means we can no longer use
a simple structure copy to copy stuff into user space.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>