[IB] Have cq_resize() method take an int, not int*

Change the struct ib_device.resize_cq() method to take a plain integer
that holds the new CQ size, rather than a pointer to an integer that
it uses to return the new size.  This makes the interface match the
exported ib_resize_cq() signature, and allows the low-level driver to
update the CQ size with proper locking if necessary.

No in-tree drivers are exporting this method yet.

Signed-off-by: Roland Dreier <rolandd@cisco.com>